criyle/codenet-compile-errors huggingface dataset:
Language: Java

import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner();
    int n = scan.nextInt();
    scan.close();
    
    int count = 0;
    for(int i = 1; i <= n; i++) {
      String len = String.valueOf(i).length();
      if(len % 2 == 1) count++;
    }
    System.out.println(count);
  }
}

Compiler output:
Main.java:5: error: no suitable constructor found for Scanner(no arguments)
    Scanner scan = new Scanner();
                   ^
    constructor Scanner.Scanner(Readable,Pattern) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(Readable) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(InputStream) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(InputStream,String) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(InputStream,Charset) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(File) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(File,String) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(File,Charset) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(File,CharsetDecoder) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(Path) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(Path,String) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(Path,Charset) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(String) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(ReadableByteChannel) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(ReadableByteChannel,String) is not applicable
      (actual and formal argument lists differ in length)
    constructor Scanner.Scanner(ReadableByteChannel,Charset) is not applicable
      (actual and formal argument lists differ in length)
Main.java:11: error: incompatible types: int cannot be converted to String
      String len = String.valueOf(i).length();
                                           ^
Main.java:12: error: bad operand types for binary operator '%'
      if(len % 2 == 1) count++;
             ^
  first type:  String
  second type: int
3 errors
Language: C++

#include <bits/stdc++.h>
using namespace std;

int main() {
  int N;
  cin>> N;
  int count=0;
    
  while(N>0){
    character=N;
    string character;
    digit=character.size(N);
    
    judgement=digit%2
    if(digit==1){
      count++;
    }
    
    N--;

 cout<<endl;
}
    
    
    
    
    
    


Compiler output:
a.cc: In function 'int main()':
a.cc:10:5: error: 'character' was not declared in this scope; did you mean 'std::filesystem::file_type::character'?
   10 |     character=N;
      |     ^~~~~~~~~
      |     std::filesystem::file_type::character
In file included from /usr/include/c++/14/filesystem:51,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:200,
                 from a.cc:1:
/usr/include/c++/14/bits/fs_fwd.h:80:18: note: 'std::filesystem::file_type::character' declared here
   80 |       block = 4, character = 5, fifo = 6, socket = 7, unknown = 8
      |                  ^~~~~~~~~
a.cc:12:5: error: 'digit' was not declared in this scope
   12 |     digit=character.size(N);
      |     ^~~~~
a.cc:14:5: error: 'judgement' was not declared in this scope
   14 |     judgement=digit%2
      |     ^~~~~~~~~
a.cc:22:2: error: expected '}' at end of input
   22 | }
      |  ^
a.cc:4:12: note: to match this '{'
    4 | int main() {
      |            ^
Language: C

#include <stdio.h>
 
int main(void)
{
  /* 変数の宣言 */
  int number,save=1;
  int digit = 0;
  int cn=0;
  scanf("%d",&input);
 
  do{
 number = save;
  /* 桁数を計算 */
  while(number!=0){
    number = number / 10;
    ++digit;
  }
 
  /* 数値の桁数を表示 */
  if(digit+1 %2 ==0){
    cn++;
  }
    save++;
  }while(input!= save -1);
 printf("%d\n",cn);
  return 0;
}

Compiler output:
main.c: In function 'main':
main.c:9:15: error: 'input' undeclared (first use in this function); did you mean 'int'?
    9 |   scanf("%d",&input);
      |               ^~~~~
      |               int
main.c:9:15: note: each undeclared identifier is reported only once for each function it appears in
Language: C

#include <stdio.h>
 
int main(void)
{
  /* 変数の宣言 */
  int number,save=1;
  int digit = 0;
  int cn=0;
  scanf("%d",&input);
 
  do{
 number = save;
  /* 桁数を計算 */
  while(number!=0){
    number = number / 10;
    ++digit;
  }
 
  /* 数値の桁数を表示 */
  if(digit+1 %2 ==0){
    cn++;
  }
    save++;
  }while(inpu!= save -1);
 printf("%d\n",cn);
  return 0;
}


Compiler output:
main.c: In function 'main':
main.c:9:15: error: 'input' undeclared (first use in this function); did you mean 'int'?
    9 |   scanf("%d",&input);
      |               ^~~~~
      |               int
main.c:9:15: note: each undeclared identifier is reported only once for each function it appears in
main.c:24:10: error: 'inpu' undeclared (first use in this function)
   24 |   }while(inpu!= save -1);
      |          ^~~~
Language: C

#include<stdio.h>
#include<stdlib.h>

int main(){
  int n,i;
  int cnt;
 scanf("%d",&n);
 
if(n>=100000){
  n=99999;
}
if(n>=10000){
  cnt=cnt+(n-10000)+1;
  n=9999;
}
if(n>=1000){
  n=999;
}
if(n>=1000){
  cnt=cnt+(n-100)+1;
  n=99;
}
if(n>=100){
  n=9;
}
if(n>=0){
  cnt=cnt+n
}
  
printf("%d",cnt);
  
}

Compiler output:
main.c: In function 'main':
main.c:27:12: error: expected ';' before '}' token
   27 |   cnt=cnt+n
      |            ^
      |            ;
   28 | }
      | ~
Language: C++

// Uneven Numbers

#include <iostream>
#include <vector>
#include <math.h>
#include <string>
#include <map>

using namespace std;

int main()
{
    long long N;
    cin >> N;

    char s[6];
    int cnt = 0;
    for (int i = 1; i <= N; i++) {
        sprintf(s, "%d", i);
        if (strlen(s)%2==1) {
            cnt++;
        }
    }
    cout << cnt;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:20:13: error: 'strlen' was not declared in this scope
   20 |         if (strlen(s)%2==1) {
      |             ^~~~~~
a.cc:8:1: note: 'strlen' is defined in header '<cstring>'; this is probably fixable by adding '#include <cstring>'
    7 | #include <map>
  +++ |+#include <cstring>
    8 |
Language: C

int main(){
  int n,i;
  int cnt;
 scanf("%d",&n);
 
if(n>=100000){
  n=99999;
}
if(n>=10000){
  cnt=cnt+(n-10000)+1;
  n=9999;
}
if(n>=1000){
  n=999;
}
if(n>=1000){
  cnt=cnt+(n-100)+1;
  n=99;
}
if(n>=100){
  n=9;
}
if(n>=0){
  cnt=cnt+n
}

Compiler output:
main.c: In function 'main':
main.c:4:2: error: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
    4 |  scanf("%d",&n);
      |  ^~~~~
main.c:1:1: note: include '<stdio.h>' or provide a declaration of 'scanf'
  +++ |+#include <stdio.h>
    1 | int main(){
main.c:4:2: warning: incompatible implicit declaration of built-in function 'scanf' [-Wbuiltin-declaration-mismatch]
    4 |  scanf("%d",&n);
      |  ^~~~~
main.c:4:2: note: include '<stdio.h>' or provide a declaration of 'scanf'
main.c:24:12: error: expected ';' before '}' token
   24 |   cnt=cnt+n
      |            ^
      |            ;
   25 | }
      | ~           
main.c:25:1: error: expected declaration or statement at end of input
   25 | }
      | ^
Language: C++

#include<iostream>
using namespace std;
int main() {
	int n; cin >> n;
	int a = n;
	int keta = 1;
	int ans = 0;
	while (a / 10 != 0) {
		keta++;
		a = a / 10;
	}
	if (keta % 2 == 0) {
		for (int i = 1; i < keta; i++) {
			if (i % 2 == 1) {
				ans += pow(10, i) - pow(10, i - 1) ;
			}
		}
	}
	else {
		for (int i = 1; i < keta; i++) {
			if (i % 2 == 1) {
				ans += pow(10, i) - 1;
			}
		}
			ans += n - pow(10, keta-1)+1;
	}
	cout << ans << endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:40: error: 'pow' was not declared in this scope
   15 |                                 ans += pow(10, i) - pow(10, i - 1) ;
      |                                        ^~~
a.cc:22:40: error: 'pow' was not declared in this scope
   22 |                                 ans += pow(10, i) - 1;
      |                                        ^~~
a.cc:25:36: error: 'pow' was not declared in this scope
   25 |                         ans += n - pow(10, keta-1)+1;
      |                                    ^~~
Language: C++

#include <iostream>

int main(){
	int N;
	
	std::cin >> N;
	
	if(N < 10){
		std::cout << N << std::endl;
		return 0;
	}
	if(N < 100){
		std::cout << "9" << std::endl;
	}
	if(N < 1000){
		std::cout << N -90 << std::endl;
		return 0;
	}
	
	if(N < 10000){
		std::cout << "909" <<std::endl;return 0;
	}
	if(N < 100000){
		std::cout << N - 9000 -90 << std::endl;return 0;
	std::cout << "90909"  <<std::endl;
	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:27:2: error: expected '}' at end of input
   27 | }
      |  ^
a.cc:3:11: note: to match this '{'
    3 | int main(){
      |           ^
Language: C++

#include<iostream>
using namespace std;
int main() {
	int n; cin >> n;
	int a = n;
	int keta = 1;
	int ans = 0;
	while (a / 10 != 0) {
		keta++;
		a = a / 10;
	}
	if (keta % 2 == 0) {
		for (int i = 1; i < keta; i++) {
			if (i % 2 == 1) {
				ans += pow(10, i) - 1;
			}
		}
	}
	else {
		for (int i = 1; i < keta; i++) {
			if (i % 2 == 1) {
				ans += pow(10, i) - 1;
			}
		}
			ans += n - pow(10, keta-1)+1;
	}
	cout << ans << endl;

}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:40: error: 'pow' was not declared in this scope
   15 |                                 ans += pow(10, i) - 1;
      |                                        ^~~
a.cc:22:40: error: 'pow' was not declared in this scope
   22 |                                 ans += pow(10, i) - 1;
      |                                        ^~~
a.cc:25:36: error: 'pow' was not declared in this scope
   25 |                         ans += n - pow(10, keta-1)+1;
      |                                    ^~~
Language: C++

#include <stdio.h>

int main(void)
{
	int i, n, digit = 1;
	scanf("%d", &n);
	i = n;
	while (i < 10)
	{
		digit++;
		i /= 10;
	}
	if (digit % 2 == 0)
		n = 10 ^ (digit - 1) - 1;
	i = n;
	while (digit >= 3)
	{
		i -= 10 ^ (--digit) - 10 ^ (--digit);
		printf("%d\n", i);
		return 0;
	}

Compiler output:
a.cc: In function 'int main()':
a.cc:21:10: error: expected '}' at end of input
   21 |         }
      |          ^
a.cc:4:1: note: to match this '{'
    4 | {
      | ^
Language: C++

#include<iostrem>
#include<cmath>

int main(){
  int n;
  int count = 0;
  cin >> n;
  
  for(int i = 1; i<n; i++){
    int a = (int)log10(i);
    if( (a+1)%2 == 1) count++;
    else i = i*10 - 1;
  }
  cout << count << endl;
  
  return 0;
}

Compiler output:
a.cc:1:9: fatal error: iostrem: No such file or directory
    1 | #include<iostrem>
      |         ^~~~~~~~~
compilation terminated.
Language: C++

#include<bits/stdc++.h>
using namespae std;
int main()
{   
   int i,r,x;
     long long n,ctr=0,c;
     for(i=1;i<=n;i++)
     {
        x=i;
       while(x>0)
           {
              r=x%10;
              x=x/10;
              c++;
           }                                                                                                      
             if(c%2!=0)
               ctr++;
     }
 cout<<ctr; 
}


Compiler output:
a.cc:2:7: error: expected nested-name-specifier before 'namespae'
    2 | using namespae std;
      |       ^~~~~~~~
a.cc: In function 'int main()':
a.cc:19:2: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   19 |  cout<<ctr;
      |  ^~~~
      |  std::cout
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:146,
                 from a.cc:1:
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
Language: C

#include<stdio.h>

int main(){
  int N;
  int digit = 0;
  int count= 0;
  int i;
   scanf("%d", &N);
  
if(N<10){
  digit = N;
}else if (N <100){
  digit  =9;
}else if(N < 1000){
  digit = 9 + (N -99); 
}else if(N < 10000){
  digit = 909;
}else if(N < 100000){
  digit = 909 + (N - 9999);
}else if(n = 100000){
  digit = 90909;
}
printf("%d", digit);
return 0;

}

Compiler output:
main.c: In function 'main':
main.c:20:10: error: 'n' undeclared (first use in this function)
   20 | }else if(n = 100000){
      |          ^
main.c:20:10: note: each undeclared identifier is reported only once for each function it appears in
Language: C++

#include<bits/stdc++.h>
usingnamespae std;
int main()
{   
   int i,r,x;
     long long n,ctr=0,c;
     for(i=1;i<=n;i++)
     {
        x=i;
       while(x>0)
           {
              r=x%10;
              x=x/10;
              c++;
           }                                                                                                      
             if(c%2!=0)
               ctr++;
     }
 cout<<ctr; 
}

Compiler output:
a.cc:2:1: error: 'usingnamespae' does not name a type
    2 | usingnamespae std;
      | ^~~~~~~~~~~~~
a.cc: In function 'int main()':
a.cc:19:2: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   19 |  cout<<ctr;
      |  ^~~~
      |  std::cout
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:146,
                 from a.cc:1:
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
Language: C++

#include <iostream>
 
using namespace std;
int main(){
  int n;
  int count = 0;
  cin >> n;
  
  for(int i = 1; i<n; i++){
    int a = (int)log10(i);
    if( (a+1)%2 == 1) count++;
    else i = i*10 - 1;
  }
  cout << count << endl;
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:10:18: error: 'log10' was not declared in this scope
   10 |     int a = (int)log10(i);
      |                  ^~~~~
Language: C++

#include <iostream>
#include <math.h>
using namespace std;
int main(void)
{

  int n,b,m,i,j;
  cin >> n;
  for(int i = 1;i < 6;i++)
  {
  	if(pow(10,i) > n)
      break;
  }
  
  switch(i)
  {
    case 1:
      m = n;
      break;
    case 2:
      m = 9;
      break;
    case 3:
      m = 9 + n - 100 + 1;
      break;
    case 4:
      m = 9 + 900;
      break;
    case 5;
      m = 9 + 900 + n - 10000 + 1;
      break;
  }
  cout << m;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:29:11: error: expected ':' before ';' token
   29 |     case 5;
      |           ^
      |           :
Language: C++

#include<bits/stdc++.h>
using namespace std;
int function(int a)   //判断一个数是几位数  
{  
    int n=1;  
    while (a)  
    {  
        a = a / 10;  
        n++;  
    }  
    return n;  
  
}  
int main(){
	int n,m,sum=0;
	cin>>n;
	for(int i=1;i<=n;i++){
		m=function(i);
		if(m%2==0){
			sum++;
		}
	}
	cout<<sum;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:18:19: error: reference to 'function' is ambiguous
   18 |                 m=function(i);
      |                   ^~~~~~~~
In file included from /usr/include/c++/14/functional:59,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53,
                 from a.cc:1:
/usr/include/c++/14/bits/std_function.h:111:11: note: candidates are: 'template<class _Signature> class std::function'
  111 |     class function;
      |           ^~~~~~~~
a.cc:3:5: note:                 'int function(int)'
    3 | int function(int a)   //判断一个数是几位数
      |     ^~~~~~~~
Language: C

#include<string.h>
#include<stdio.h>
#include<stdlib.h>
//using namespace std;
int main()
{
char str[100000];
int j,i,t,s,s1=0,cnt=0;

scanf("%d",&t);
for(i=1;i<=t;i++){
   itoa(i,str,10);
   j=0;
   s=0;
   while(str[j]!='\0'){
    j++;
    s++;
   }
       if(s%2!=0){
        cnt++;
    }
}
printf("%d\n",cnt);

    return 0;
}


Compiler output:
main.c: In function 'main':
main.c:12:4: error: implicit declaration of function 'itoa' [-Wimplicit-function-declaration]
   12 |    itoa(i,str,10);
      |    ^~~~
Language: C++

n = int(input())

if (n < 100):
    print(min(n, 9))
elif (n < 10000):
    print(min(n - 90, 909))
else:
    print(min(n - 9090, 90909))


Compiler output:
a.cc:1:1: error: 'n' does not name a type
    1 | n = int(input())
      | ^
Language: C++

#include<cstring>
#include<iostream>
#include<cstdlib>
using namespace std;
int main()
{
char str[100000];
int j,i,t,s,s1=0,cnt=0;

cin>>t;
for(i=1;i<=t;i++){
   itoa(i,str,10);
   j=0;
   s=0;
   while(str[j]!='\0'){
    j++;
    s++;
   }
       if(s%2!=0){
        cnt++;
    }
}
cout<<cnt<<endl;

    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:12:4: error: 'itoa' was not declared in this scope
   12 |    itoa(i,str,10);
      |    ^~~~
Language: C++

#include <iostream>
 
int main() {
  int N;
  std::cin >> N;
  uin32_t res = 0;
  if(N > 0 && N < 100) {
    res += std::min(N, 9);
  } else if(N > 99 && N < 1000) {
    // 1桁
    res += 9;
    // 3桁
    int buf = ((N / 100) -1) * 100;
    res += std::min(900, buf + (N - (buf+100)) + 1);
  } else if(N > 9999 && N <= 100000) {
    // 1桁
    res += 9;
    // 3桁
    int buf = ((N / 100) -1) * 100;
    res += std::min(900, buf + (N - (buf+100)) + 1);
    // 5桁
    buf = ((N / 10000) - 1) * 10000;
    res += std::min(buf + (N - (buf+10000) + 1), 90000);
  }
  std::cout << res << std::endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:6:3: error: 'uin32_t' was not declared in this scope; did you mean 'u_int32_t'?
    6 |   uin32_t res = 0;
      |   ^~~~~~~
      |   u_int32_t
a.cc:8:5: error: 'res' was not declared in this scope
    8 |     res += std::min(N, 9);
      |     ^~~
a.cc:11:5: error: 'res' was not declared in this scope
   11 |     res += 9;
      |     ^~~
a.cc:17:5: error: 'res' was not declared in this scope
   17 |     res += 9;
      |     ^~~
a.cc:25:16: error: 'res' was not declared in this scope
   25 |   std::cout << res << std::endl;
      |                ^~~
Language: C++

#include<cstring>
#include<iostream>
#include<cstdlib>
using namespace std;
int main()
{
char str[1000];
int j,i,t,s,s1=0,cnt=0;

cin>>t;
for(i=1;i<=t;i++){
   itoa(i,str,10);
   j=0;
   s=0;
   while(str[j]!='\0'){
    j++;
    s++;
   }
       if(s%2!=0){
        cnt++;
    }
}
cout<<cnt<<endl;

    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:12:4: error: 'itoa' was not declared in this scope
   12 |    itoa(i,str,10);
      |    ^~~~
Language: C++

#include<iostream>
using namespace std;
int main(){
  int n;
  cin >> n;
  int a;
  if(n<10){
    cout<<n;
  }else if(n<100){
    cout<<9;
  }else if(n<1000){
    a=n-99;
    cout<<(9+a);
  }else if(n<10000){
    cout<<909;
  }else if(n<100000){
    a=n-9999
    cout<<(909+a);
  }else{
    cout<<90909;
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:17:13: error: expected ';' before 'cout'
   17 |     a=n-9999
      |             ^
      |             ;
   18 |     cout<<(909+a);
      |     ~~~~
Language: C++

#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
#include<queue>
#include<limits>

using namespace std;

int main(){
    int n; cin >> n;

    int t = 1, nd = n;
    while(nd/10 > 0){
        ++t;
        nd /= 10;
    }

    int ans = 0;

    for(int i=1; pow(10, i)<=n; i+=2){
        ans += pow(10, i) - 1 - pow(10, i-1) + 1;
    }

    if(t & 0b1) ans += n - pow(10, t-1) + 1;

    cout << ans << endl;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:21:18: error: 'pow' was not declared in this scope
   21 |     for(int i=1; pow(10, i)<=n; i+=2){
      |                  ^~~
a.cc:25:28: error: 'pow' was not declared in this scope
   25 |     if(t & 0b1) ans += n - pow(10, t-1) + 1;
      |                            ^~~
Language: Java

import java.util.Scanner;

public class MainA2 {
	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		long n = sc.nextLong();

		if (n<10) {
			System.out.println(n);
		}else if (n< 100) {
			System.out.println(9);
		}else if (n< 1000) {
			System.out.println(9+n-99);
		}else if (n< 10000) {
			System.out.println(909);
		}else if (n< 100000) {
			System.out.println(909+n-9999);
		}else {
			System.out.println(90909);
		}
		
		sc.close();
	}

}

Compiler output:
Main.java:3: error: class MainA2 is public, should be declared in a file named MainA2.java
public class MainA2 {
       ^
1 error
Language: C

#include<stdio.h>
#include<stdlib.h>
 
int main(){
  int number;
  int connt=0;
  scanf("%d",&number);
  
  while(number>=1000){
    number--;
  }
  while(number>=100){
    number--;
    count++;
  }
  while(number>=10){
    number--;
  }
  while(number>=0){
    number--;
    count++;
  }
  printf("%d",&count);
    
}

Compiler output:
main.c: In function 'main':
main.c:14:5: error: 'count' undeclared (first use in this function); did you mean 'connt'?
   14 |     count++;
      |     ^~~~~
      |     connt
main.c:14:5: note: each undeclared identifier is reported only once for each function it appears in
Language: C

#include<stdio.h>
#include<stdlib.h>

int main(){
  int number;
  int connt=0;
  scanf("%d",&number);
  
  while(number>=1000){
    number--;
  }
  while(number>=100){
    number--;
    count++;
  }
  while(number>=10){
    number--;
  }
  while(number>=0){
    number--;
    count++;
  }
  printf("%d",&count)+
    
}

Compiler output:
main.c: In function 'main':
main.c:14:5: error: 'count' undeclared (first use in this function); did you mean 'connt'?
   14 |     count++;
      |     ^~~~~
      |     connt
main.c:14:5: note: each undeclared identifier is reported only once for each function it appears in
main.c:25:1: error: expected expression before '}' token
   25 | }
      | ^
Language: C++

#include<bits/stdc++.h>
using namespace std;

int main()
{
	int i;
	cin >> i;
    if(i < 10){
    	cout << i << endl;
    	return 0;
	}else if(i < 100){
		cout << 9 << endl;
		return 0;
	}else if(i < 1000){
		cout << 10 + i - 100 << endl;
		return 0;
	}else if(i < 10000){
		cout << 909;
		return 0;
	}else if(i < 100000){
		cout << 910 + i - 10000 << endl;
		return 0;
	}else{
		cout << 90909 <<9 endl;
		return 0;
	}
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:24:34: error: expected ';' before 'endl'
   24 |                 cout << 90909 <<9 endl;
      |                                  ^~~~~
      |                                  ;
Language: C++

#include <iostream>
#include <cmath>
using namespace std;
int main() {
  int N,answer ;
  cin >> N;
  int n = N;
  int m = 1; //桁数
  do{
    n /= 10;
    m++;
  }while(n > 0);
  
  for(int i = 0; i < m-1 ; ++i){
    if(i%2 == 0)continue;
    answer += 9 * pow(10,m-1);
  }
  
  if(m%2 == 0)cout << answer;
  
  int t =1;
  for(int i = 0; i < m ;++i){
    t *= (N / pow(10,i) ) % 10;
  }
  answer += t;
  
  cout << answer;
  
  
  
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:23:27: error: invalid operands of types '__gnu_cxx::__promote<double>::__type' {aka 'double'} and 'int' to binary 'operator%'
   23 |     t *= (N / pow(10,i) ) % 10;
      |          ~~~~~~~~~~~~~~~~ ^ ~~
      |             |               |
      |             |               int
      |             __gnu_cxx::__promote<double>::__type {aka double}
Language: C++

#include<iostream>
using namespace std;
int main()
{ 
  long long  int n,d,res,count;
  count=0;
  cin>>n;
  int i=1;
  while(i<=n)
  {  d=i;
     while(d>0)
     {
       d=d/10;
       count++;
     
     }
   if(count%2!=0)
   res++;
  }
 }
  cout<<res;
return 0;
}

Compiler output:
a.cc:21:3: error: 'cout' does not name a type
   21 |   cout<<res;
      |   ^~~~
a.cc:22:1: error: expected unqualified-id before 'return'
   22 | return 0;
      | ^~~~~~
a.cc:23:1: error: expected declaration before '}' token
   23 | }
      | ^
Language: Java

class TaskA {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();

        int total = 0;

        for (int i = 1; i <= a; i++) {
            if (String.valueOf(i).length() % 2 == 1) total++;
        }
        System.out.println(total);
    }
}

Compiler output:
Main.java:3: error: cannot find symbol
        Scanner sc = new Scanner(System.in);
        ^
  symbol:   class Scanner
  location: class TaskA
Main.java:3: error: cannot find symbol
        Scanner sc = new Scanner(System.in);
                         ^
  symbol:   class Scanner
  location: class TaskA
2 errors
Language: C++

#include <iostream>
#include <cmath>
using namespace std;
int main() {
  int N,answer ;
  cin >> N;
  int n = N;
  int m = 1; //桁数
  do{
    n /= 10;
    m++;
  }while(n > 0);
  
  for(int i = 0; i < m-1 ; ++i){
    if(i%2 == 0)continue;
    answer += 9 * pow(10,m-1);
  }
  
  if(m%2 == 0)cout << answer;
  
  int t =1;
  for(int i = 0; i < m ;++i){
    t *= (N / pow(10,i) ) %10;
  }
  answer += t;
  
  cout << answer;
  
  
  
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:23:27: error: invalid operands of types '__gnu_cxx::__promote<double>::__type' {aka 'double'} and 'int' to binary 'operator%'
   23 |     t *= (N / pow(10,i) ) %10;
      |          ~~~~~~~~~~~~~~~~ ^~~
      |             |              |
      |             |              int
      |             __gnu_cxx::__promote<double>::__type {aka double}
Language: C++

#include <iostream>
using namespace std;
int main() {
  int N,answer ;
  cin >> N;
  int n = N;
  int m = 1; //桁数
  do{
    n /= 10;
    m++;
  }while(n > 0);
  
  for(int i = 0; i < m-1 ; ++i){
    if(i%2 == 0)continue;
    answer += 9 * std::pow(10,m-1);
  }
  
  if(m%2 == 0)cout << answer;
  
  int t =1;
  for(int i = 0; i < m ;++i){
    t *= (N / std::pow(10,i) ) %10;
  }
  answer += t;
  
  cout << answer;
  
  
  
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:15:24: error: 'pow' is not a member of 'std'
   15 |     answer += 9 * std::pow(10,m-1);
      |                        ^~~
a.cc:22:20: error: 'pow' is not a member of 'std'
   22 |     t *= (N / std::pow(10,i) ) %10;
      |                    ^~~
Language: C++

#include <iostream>
using namespace std;
int main() {
  int N,answer ;
  cin >> N;
  int n = N;
  int m = 1; //桁数
  do{
    n /= 10;
    m++;
  }while(n > 0);
  
  for(int i = 0; i < m-1 ; ++i){
    if(i%2 == 0)continue;
    answer += 9 * pow(10,m-1);
  }
  
  if(m%2 == 0)cout << answer;
  
  int t =1;
  for(int i = 0; i < m ;++i){
    t *= (N / pow(10,i) ) %10;
  }
  answer += t;
  
  cout << answer;
  
  
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:19: error: 'pow' was not declared in this scope
   15 |     answer += 9 * pow(10,m-1);
      |                   ^~~
a.cc:22:15: error: 'pow' was not declared in this scope
   22 |     t *= (N / pow(10,i) ) %10;
      |               ^~~
Language: C++

#include<iostream>
using namespace std;
int main(){
  int n;
  cin>>n;
  int cnt=0;
  for(int i=1;i<=N;i=i*10){
    cnt++;
    if(cnt%2==1){
      for(int j=i;j<i*10;j++) 
        if(j<=n)  cout<<j;
    }
    else continue;
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:18: error: 'N' was not declared in this scope
    7 |   for(int i=1;i<=N;i=i*10){
      |                  ^
Language: C++

#include <bits/stdc++.h>
using namespace std;

int main() {
  int N;
  cin>>N;

  if(N/10==0){
    cout<<N<<endl;
  }
  else if(N/100==0){
    cout<<9<<endl:
  }
  else if(N/1000==0){
    cout<<N-90<<endl;
  }
  else if(N/10000==0){
    cout<<909<<endl;
  }
  else if(N/100000==0){
    cout<<N-9090<<endl;
  }
  else{
    cout<<90909<<endl;
  }
             
}


Compiler output:
a.cc: In function 'int main()':
a.cc:12:18: error: expected ';' before ':' token
   12 |     cout<<9<<endl:
      |                  ^
      |                  ;
Language: C++

#include<iostream>
using namespace std;

int main(){
  int N;
  cin >> N;
  int num10_4=90000;
  int num10_2=900;
  int num10_0=9;
  
  if(N==100000){
    cout << 90909;
  }else if(N>=10**4){
    cout << num10_0+num10_2+N-10**4+1;
  }else if(N>=10**3){
    cout << 909;
  }else if(N>=10**2){
    cout << num10_0+N-10**2+1;
  }else if(N>=10){
    cout << 9;
  }else{
    cout << N;
  }
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:13:18: error: invalid type argument of unary '*' (have 'int')
   13 |   }else if(N>=10**4){
      |                  ^~
a.cc:14:34: error: invalid type argument of unary '*' (have 'int')
   14 |     cout << num10_0+num10_2+N-10**4+1;
      |                                  ^~
a.cc:15:18: error: invalid type argument of unary '*' (have 'int')
   15 |   }else if(N>=10**3){
      |                  ^~
a.cc:17:18: error: invalid type argument of unary '*' (have 'int')
   17 |   }else if(N>=10**2){
      |                  ^~
a.cc:18:26: error: invalid type argument of unary '*' (have 'int')
   18 |     cout << num10_0+N-10**2+1;
      |                          ^~
Language: Java

import java.util.Scanner;

public class Main2 {

	public static void main(String[] args) {
		Scanner stdIn=new Scanner(System.in);
		int n=stdIn.nextInt();
//		int b=stdIn.nextInt();
//		int c=stdIn.nextInt();
		//int valen[]=new int[n+1];
		int cnt=0;
		for(int i=1;i<=n;i++) {
			int valen=String.valueOf(i).length();
			if((valen%2)==1) {
				cnt++;
			}
		}
		System.out.println(cnt);

	}

}


Compiler output:
Main.java:3: error: class Main2 is public, should be declared in a file named Main2.java
public class Main2 {
       ^
1 error
Language: C

#include <stdio.h>
int main(){
int n,i;
scanf("%d",&n);
{
if(1<=n&&n<=9)
i=n;
else if(10<=n&&n<=99)
i=9;
else if(100<=n&&n<=999)
i=9;
i+=n-99;
else if(1000<=n&&n<=9999)
i=909;
else if(10000<=n&&n<=99999)
i=909;
i+=n-9999;
else if(n==100000)
i=90909;
}
printf("%d",i);
}

Compiler output:
main.c: In function 'main':
main.c:13:1: error: 'else' without a previous 'if'
   13 | else if(1000<=n&&n<=9999)
      | ^~~~
main.c:18:1: error: 'else' without a previous 'if'
   18 | else if(n==100000)
      | ^~~~
Language: C++

#include<stdio.h>
int main(){
    int N,i;
    int cnt = 0;
    int digit = 0;

    scanf("%d", &N);

    for(i =1; i <= N, i++){
        while (i != 0)
        {
            i = i/10;
            ++digit;
        }
        if(digit%2 == 1){
            cnt++;
        }
    }

    printf("%d", cnt);

    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:26: error: expected ';' before ')' token
    9 |     for(i =1; i <= N, i++){
      |                          ^
      |                          ;
Language: C++

#include <bits/stdc++.h>
using namespace std;

int main(){
  int n;
  cin>>n;
  if(n>=10^5){
    cout<<90000+900+9<<endl;
  }else if(n>=10^4){
    cout<<n-10^4+909<<endl;
  }else if(n>=10^3){
    cout<<909<<endl;
  }else if(n>=10^2){
    cout<<n-100+9<<endl;
  }else if(n>=10){
    cout<<9<<endl;
  }else{
    cout<<n<<endl;
  }
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:10:21: error: invalid operands of types 'int' and '<unresolved overloaded function type>' to binary 'operator<<'
   10 |     cout<<n-10^4+909<<endl;
      |                ~~~~~^~~~~~
Language: C++

#include<bits/stdc++.h>
#include<bitset>
using namespace std;

int main(){
	int N;
	cin>>N;
	
	if(N<10)
		cout<<N;
	else if(N<100)
		cout<<9;
	else if(N<1000)
		cout<<9+(N-99)
	else if(N<10000)
		cout<<9+900;
	else if(N<100000)
		cout<<9+900+(N-9999);
	else if(N==100000)
		cout<<9+900+90000;
		
	
	
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:14:31: error: expected ';' before 'else'
   14 |                 cout<<9+(N-99)
      |                               ^
      |                               ;
   15 |         else if(N<10000)
      |         ~~~~
Language: Java

import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
    
		// 整数の入力
		int n = sc.nextInt();
      
        int ans = 0;
      　　    
		if (n >= 10000) {
          ans += 909;
          ans += (n - 9999);
        } else if (n >= 100) {
          ans += 9;
          ans += (n - 99);
        } else if (n >= 10) {
          ans = 9;
        } else {
          ans = n;
        }
    
		// 出力
		System.out.println(ans);
	}
}


Compiler output:
Main.java:10: error: illegal character: '\u3000'
      ??    
      ^
Main.java:10: error: illegal character: '\u3000'
      ??    
       ^
2 errors
Language: C++

#include <iostream>
#include <string>

int main()
{
	std::string s;
	int n;
	std::cin >> n;
	int counter = 0;
	for (int i = 1; i <= n; i++) {
		s = to_string(i);
		counter = s.length() % 2 == 1 ? counter+1 : counter;
	}

	std::cout << counter;
   return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:11:21: error: 'to_string' was not declared in this scope; did you mean 'std::__cxx11::to_string'?
   11 |                 s = to_string(i);
      |                     ^~~~~~~~~
      |                     std::__cxx11::to_string
In file included from /usr/include/c++/14/string:54,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/basic_string.h:4421:3: note: 'std::__cxx11::to_string' declared here
 4421 |   to_string(long double __val)
      |   ^~~~~~~~~
Language: C

#include <stdio.h>
int main(){
int n,i=0;
scanf("%d",&n);
if(1<=n&&n<=9)
i=n;
if(10<=n&&n<=99)
i=9;
if(100<=n&&n<=999)
i=9;
i+=n-99;
if(1000<=n&&n<=9999)
i=909;
if(10000<=n&&n<=99999)
i=909;
i+=n-9999;
if(n==100000)
i=90909;
}
printf("%d",i);
}

Compiler output:
main.c:20:8: error: expected declaration specifiers or '...' before string constant
   20 | printf("%d",i);
      |        ^~~~
main.c:20:13: error: unknown type name 'i'
   20 | printf("%d",i);
      |             ^
main.c:21:1: error: expected identifier or '(' before '}' token
   21 | }
      | ^
Language: C++

#include <bits/stdc++.h>
using namespace std;

int main() {
  int N;
  cin >> N;
  if (N >= 1 && N <10) {
  cous << N <<endl;
  }  
  if (N >= 10 && N <100) {
  cous << 9 <<endl;
  }  
  if (N >= 100 && N <1000) {
  cous << N - 90 <<endl;
  }  
  if (N >= 1000 && N <10000) {
  cous << N - 90 <<endl;
  }  
  if (N >= 10000 && N <100000) {
  cous << 2 * N - 10089 <<endl;
  }  
  if (N == 100000) {
  cous << 90909 <<endl;
  }  
}


Compiler output:
a.cc: In function 'int main()':
a.cc:8:3: error: 'cous' was not declared in this scope; did you mean 'cos'?
    8 |   cous << N <<endl;
      |   ^~~~
      |   cos
a.cc:11:3: error: 'cous' was not declared in this scope; did you mean 'cos'?
   11 |   cous << 9 <<endl;
      |   ^~~~
      |   cos
a.cc:14:3: error: 'cous' was not declared in this scope; did you mean 'cos'?
   14 |   cous << N - 90 <<endl;
      |   ^~~~
      |   cos
a.cc:17:3: error: 'cous' was not declared in this scope; did you mean 'cos'?
   17 |   cous << N - 90 <<endl;
      |   ^~~~
      |   cos
a.cc:20:3: error: 'cous' was not declared in this scope; did you mean 'cos'?
   20 |   cous << 2 * N - 10089 <<endl;
      |   ^~~~
      |   cos
a.cc:23:3: error: 'cous' was not declared in this scope; did you mean 'cos'?
   23 |   cous << 90909 <<endl;
      |   ^~~~
      |   cos
Language: C++


#include <iostream>

int main()
{
	std::string s;
	int n;
	std::cin >> n;
	int counter = 0;
	for (int i = 1; i <= n; i++) {
		s = to_string(i);
		counter = s.length() % 2 == 1 ? counter+1 : counter;
	}

	std::cout << counter;
   return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:11:21: error: 'to_string' was not declared in this scope; did you mean 'std::__cxx11::to_string'?
   11 |                 s = to_string(i);
      |                     ^~~~~~~~~
      |                     std::__cxx11::to_string
In file included from /usr/include/c++/14/string:54,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:2:
/usr/include/c++/14/bits/basic_string.h:4421:3: note: 'std::__cxx11::to_string' declared here
 4421 |   to_string(long double __val)
      |   ^~~~~~~~~
Language: C++

#include <bits/stdc++.h>
using namespace std;

int main() {
  int n;
  scanf("%d",&n);
  if(n<10){
      printf("%d",n);
  }else if(n<100){
      printf("9");
  }else if (n<1000){
      printf("%d",n-90);
  }else if(n<10000){
      printf("909");
  }else if(n<100000){
      printf("%d", n-9090);
  }else{
      printf("90909")
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:18:22: error: expected ';' before '}' token
   18 |       printf("90909")
      |                      ^
      |                      ;
   19 |   }
      |   ~
Language: C++

#include <iostream>
#include <string>

using namespace std;

int main()
{
	int n;
	int num;
	int ans=0;
	int i;
	cin >> n;
	
	num = to_string(n).length();

	for (i = 1; i < num; i += 2)
	{
		ans += 9 * (int)(pow(10, i-1) + 0.5);
	}

	if (num % 2 != 0)
	{
		n -= (int)(pow(10, num - 1) + 0.5);
	}

	cout << ans + n + 1;

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:18:34: error: 'pow' was not declared in this scope
   18 |                 ans += 9 * (int)(pow(10, i-1) + 0.5);
      |                                  ^~~
a.cc:23:28: error: 'pow' was not declared in this scope
   23 |                 n -= (int)(pow(10, num - 1) + 0.5);
      |                            ^~~
Language: C++

if (n>9999 && n<=99999)
	{
		ans=n-9090;
	}
	if (n>999 && n<=9999)
	{
		ans=909;
	}
	if (n>99 && n<=999)
	{
		ans=n-90;
	}
	if (n>9 && n<=99)
	{
		ans=9;
	}
	if (n<=9)
	{
		ans=n;
	}
	if (n==100000)
	{
		ans=90909;
	}

Compiler output:
a.cc:1:1: error: expected unqualified-id before 'if'
    1 | if (n>9999 && n<=99999)
      | ^~
a.cc:5:9: error: expected unqualified-id before 'if'
    5 |         if (n>999 && n<=9999)
      |         ^~
a.cc:9:9: error: expected unqualified-id before 'if'
    9 |         if (n>99 && n<=999)
      |         ^~
a.cc:13:9: error: expected unqualified-id before 'if'
   13 |         if (n>9 && n<=99)
      |         ^~
a.cc:17:9: error: expected unqualified-id before 'if'
   17 |         if (n<=9)
      |         ^~
a.cc:21:9: error: expected unqualified-id before 'if'
   21 |         if (n==100000)
      |         ^~
Language: C++

int main() {
  int n;
  cin>>n;
  if(n>=10000&&n!=100000){
    cout<<n-9999+909<<endl;
  }else if(n>=1000&&n<10000){
    cout<<899<<endl;
  }else if(n>=100&&n<=999){
    cout<<n-99+9<<endl;
  }else if(n>=10&&n<100){
    cout<<9<<endl;
  }else if(n>=1&&n<10){
    cout<<n<<endl;
  }else if(n==100000){
    cout<<90909<<endl;
  }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:3:3: error: 'cin' was not declared in this scope
    3 |   cin>>n;
      |   ^~~
a.cc:5:5: error: 'cout' was not declared in this scope
    5 |     cout<<n-9999+909<<endl;
      |     ^~~~
a.cc:5:23: error: 'endl' was not declared in this scope
    5 |     cout<<n-9999+909<<endl;
      |                       ^~~~
a.cc:7:5: error: 'cout' was not declared in this scope
    7 |     cout<<899<<endl;
      |     ^~~~
a.cc:7:16: error: 'endl' was not declared in this scope
    7 |     cout<<899<<endl;
      |                ^~~~
a.cc:9:5: error: 'cout' was not declared in this scope
    9 |     cout<<n-99+9<<endl;
      |     ^~~~
a.cc:9:19: error: 'endl' was not declared in this scope
    9 |     cout<<n-99+9<<endl;
      |                   ^~~~
a.cc:11:5: error: 'cout' was not declared in this scope
   11 |     cout<<9<<endl;
      |     ^~~~
a.cc:11:14: error: 'endl' was not declared in this scope
   11 |     cout<<9<<endl;
      |              ^~~~
a.cc:13:5: error: 'cout' was not declared in this scope
   13 |     cout<<n<<endl;
      |     ^~~~
a.cc:13:14: error: 'endl' was not declared in this scope
   13 |     cout<<n<<endl;
      |              ^~~~
a.cc:15:5: error: 'cout' was not declared in this scope
   15 |     cout<<90909<<endl;
      |     ^~~~
a.cc:15:18: error: 'endl' was not declared in this scope
   15 |     cout<<90909<<endl;
      |                  ^~~~
Language: C

#include <stdio.h>
int main(){
int n,i=0;
scanf("%d",&n);
{if(1<=n&&n<=9)
i=n;
else if(10<=n&&n<=99)
i=9;
else if(100<=n&&n<=999)
i=9;
i+=n-99;
else if(1000<=n&&n<=9999)
i=909;
else if(10000<=n&&n<=99999)
i=909;
i+=n-9999;
else (n==100000)
i=90909;
}
printf("%d",i);
}

Compiler output:
main.c: In function 'main':
main.c:12:1: error: 'else' without a previous 'if'
   12 | else if(1000<=n&&n<=9999)
      | ^~~~
main.c:17:1: error: 'else' without a previous 'if'
   17 | else (n==100000)
      | ^~~~
main.c:17:17: error: expected ';' before 'i'
   17 | else (n==100000)
      |                 ^
      |                 ;
   18 | i=90909;
      | ~
Language: C++

#include<bits/stdc++.h>
using namespace std;
int check(int val)
{
  int cnt=0;
  while(check>0)
  {
    cnt++;
  check=check/10;
  }
  if(cnt&1)
    return 1;
  return 0;
}
int main()
{
int n;
  cin>>n;
  int ans=0;
  for(int i=1;i<n;i++)
  {
    if(check(i))
      ans++;
  }
  cout<<ans;
}

Compiler output:
a.cc: In function 'int check(int)':
a.cc:6:14: error: ordered comparison of pointer with integer zero ('int (*)(int)' and 'int')
    6 |   while(check>0)
      |         ~~~~~^~
a.cc:9:14: error: invalid operands of types 'int(int)' and 'int' to binary 'operator/'
    9 |   check=check/10;
      |         ~~~~~^~~
      |         |     |
      |         |     int
      |         int(int)
Language: C++

n=int(input())
if n < 10:
    print(n)
elif n < 100:
    print(9)
elif n < 1000:
    print(n - 99 + 9)
elif n < 10000:
    print(909)
elif n < 100000:
    print(n - 9999 + 909)
elif n < 1000000:
    print(90909)


Compiler output:
a.cc:1:1: error: 'n' does not name a type
    1 | n=int(input())
      | ^
Language: C++

#include<bits/stdc++.h>
using namespace std;
int check(int val)
{
  int cnt=0;
  while(check>0)
  {
    cnt++;
  check=check/10;
  }
  if(cnt&1)
    return 1;
  return 0;
}
int main()
{
int n;
  cin>>n;
  int ans=0;
  for(int i=1;i<n;i++)
  {
    if(check(i))
      ans++;
  }
  cout<<ans;

Compiler output:
a.cc: In function 'int check(int)':
a.cc:6:14: error: ordered comparison of pointer with integer zero ('int (*)(int)' and 'int')
    6 |   while(check>0)
      |         ~~~~~^~
a.cc:9:14: error: invalid operands of types 'int(int)' and 'int' to binary 'operator/'
    9 |   check=check/10;
      |         ~~~~~^~~
      |         |     |
      |         |     int
      |         int(int)
a.cc: In function 'int main()':
a.cc:25:13: error: expected '}' at end of input
   25 |   cout<<ans;
      |             ^
a.cc:16:1: note: to match this '{'
   16 | {
      | ^
Language: C

#include <stdio.h>
int main(){
int n,i=0;
scanf("%d",&n);
{if(1<=n&&n<=9)
i=n;
else if(10<=n&&n<=99)
i=9;
else if(100<=n&&n<=999)
i=9;
i+=n-99;
else if(1000<=n&&n<=9999)
i=909;
else if(10000<=n&&n<=99999)
i=909;
i+=n-9999;
else if(n==100000)
i=90909;
printf("%d",i);
}
}

Compiler output:
main.c: In function 'main':
main.c:12:1: error: 'else' without a previous 'if'
   12 | else if(1000<=n&&n<=9999)
      | ^~~~
main.c:17:1: error: 'else' without a previous 'if'
   17 | else if(n==100000)
      | ^~~~
Language: C++

#include<bits/stdc++.h>
using namespace std;

int main(){
	int n;
	cin>>n;
	if(n<=9)cout<<n;
	else if(n<=999)cout<<9+n-100+1;
	else if(n<=99999)cout<<9+899+1++1+n-10000;
		
	
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:38: error: lvalue required as increment operand
    9 |         else if(n<=99999)cout<<9+899+1++1+n-10000;
      |                                      ^
Language: Java

import java.util.*;
public class Main{
  public static void main(String[] args){
    int n = sc.nextInt();
    int count =0;
    for(int i=1;i<=n;i++){
      String h = Integer.toString(i);
      int l = h.length();
      if(l%2!=0){
        count++;
    }
      System.out.println(count);
  }
    
}



Compiler output:
Main.java:15: error: reached end of file while parsing
}
 ^
1 error
Language: C++

#include<bits/stdc++.h>
using namespace std;
int main(){
 int n;
 cin >> n;
 if(n>=10000){
    cout << n-9998 << endl;
 }else if(n>=1000){
    cout << 909 << endl;
 }else if(n>=100){
  cout << n-98 << endl;
}else if(n>=10){
cout << 9 << endl;
}else{
cout << n << endl;
}
]

Compiler output:
a.cc: In function 'int main()':
a.cc:17:1: error: expected primary-expression before ']' token
   17 | ]
      | ^
a.cc:17:2: error: expected '}' at end of input
   17 | ]
      |  ^
a.cc:3:11: note: to match this '{'
    3 | int main(){
      |           ^
Language: C++

#include <iostream>
#include <sstream>
#include <algorithm>
#include <cstring>
#include <tuple>
#include <vector>
#include <map>
#include <iterator>

using namespace std;
using lint = long long int;

int main() {
	int n;
	cin >> n;

	int count = 0;
	for (int digit = 1; ; digit+=2) {
		int max = pow(10, digit) - 1;
		int min = pow(10, digit - 1);
		if (min > n)
			break;
		int max2 = std::min(max, n);
		count += max2 - min + 1;
		if (max2 == n)
			break;
	}
	cout << count;

	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:19:27: error: 'pow' was not declared in this scope
   19 |                 int max = pow(10, digit) - 1;
      |                           ^~~
Language: C

#include <stdio.h>
int main(){
int n,i=0;
scanf("%d",&n);
if(1<=n&&n<=9)
i=n;
else if(10<=n&&n<=99)
i=9;
else if(100<=n&&n<=999)
i=9;
i+=n-99;
else if(1000<=n&&n<=9999)
i=909;
else if(10000<=n&&n<=99999)
i=909;
i+=n-9999;
else if(n==100000)
i=90909;
printf("%d",i);
}

Compiler output:
main.c: In function 'main':
main.c:12:1: error: 'else' without a previous 'if'
   12 | else if(1000<=n&&n<=9999)
      | ^~~~
main.c:17:1: error: 'else' without a previous 'if'
   17 | else if(n==100000)
      | ^~~~
Language: C++

#include <iostream>
#include <string>

using namespace std;

int main(){
    int N,count=0;
    cin >>N;
    string a;
    a=to_string(N);
    int A=a.length;
    if(A==1||A==2){
        cout <<N;
    }else if(A==3||A==4){
        cout <<9+A-99;
    }else if(A==5){
        cout <<9+900+A-9999;
    }
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:11:13: error: cannot convert 'std::__cxx11::basic_string<char>::length' from type 'std::__cxx11::basic_string<char>::size_type (std::__cxx11::basic_string<char>::)() const noexcept' {aka 'long unsigned int (std::__cxx11::basic_string<char>::)() const noexcept'} to type 'int'
   11 |     int A=a.length;
      |             ^~~~~~
Language: C++

#include<iostream>
#include<vector>
#include<string>
#include<algorithm>
#include<cstdlib>
#define REP(i,n) for(int i=0, i##_len=(n); i<i##_len; ++i)
using ll = long long;
using namespace std;
int GetDig(int n) {
	return (int)(log10(n)) + 1;
}
int main() {
	int n;
	cin >> n;
	int cnt = 0;
	REP(i,n){
		GetDig(i + 1) % 2 ? cnt++ : 0;
	}
	cout << cnt << endl;
	return 0;
}

Compiler output:
a.cc: In function 'int GetDig(int)':
a.cc:10:22: error: 'log10' was not declared in this scope
   10 |         return (int)(log10(n)) + 1;
      |                      ^~~~~
Language: C++

#include <iostream>
#include <string>
#include <algorithm>
using namespace std;

int main() {
    int N;
    cin >> N;

    int count = 0;
    for (int i = N;  i >= 1  ; --i) {
        if (std::to_string(i).length % 2 == 1){
            count++;
        }
    }

    cout << count << endl;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:12:31: error: invalid use of member function 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::length() const [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; size_type = long unsigned int]' (did you forget the '()' ?)
   12 |         if (std::to_string(i).length % 2 == 1){
      |             ~~~~~~~~~~~~~~~~~~^~~~~~
      |                                     ()