criyle/codenet-compile-errors huggingface dataset:
Language: C++

#include <iostream>
#include <cstdlib>
#include <vector>
#include <algorithm>
#include <string>
#include <cmath>
#include <new>
#include <map>

using namespace std;
 
int main() {
	int a,ans;
	cin >> a;
for(int i = 1;i <= 9;i++){
	if(0 <= a && a <= 9){
		ans++;
}

for(int i = 100;i <= 9999;i++){
	if(100 <= a && a <= 9999){
		ans++;
}

for(int i = 10000;i <= 99999;i++){
	if(10000 <= a && a <= 99999){
		ans++;
}
	cout << ans << endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:31:2: error: expected '}' at end of input
   31 | }
      |  ^
a.cc:20:31: note: to match this '{'
   20 | for(int i = 100;i <= 9999;i++){
      |                               ^
a.cc:31:2: error: expected '}' at end of input
   31 | }
      |  ^
a.cc:15:26: note: to match this '{'
   15 | for(int i = 1;i <= 9;i++){
      |                          ^
a.cc:31:2: error: expected '}' at end of input
   31 | }
      |  ^
a.cc:12:12: note: to match this '{'
   12 | int main() {
      |            ^
Language: C++

#include<iostream>

using namespace std;

int main(){
    int N;
    cin >> N;
    if(0<N<10){
        cout << N << ¥n;
    } else if(10<=N<100){
        cout << 9 << ¥n;
    } else if(100<=N<1000){
        cout << N+10 << ¥n;
    } else if(1000<=N<10000){
        cout << 909 << ¥n;
    } else if(10000<=N<100000){
        cout << N+910 << ¥n;
    } else if(100000==N){
        cout << 90909 << ¥n;
    }
}

Compiler output:
a.cc:9:22: error: extended character ¥ is not valid in an identifier
    9 |         cout << N << ¥n;
      |                      ^
a.cc:11:22: error: extended character ¥ is not valid in an identifier
   11 |         cout << 9 << ¥n;
      |                      ^
a.cc:13:25: error: extended character ¥ is not valid in an identifier
   13 |         cout << N+10 << ¥n;
      |                         ^
a.cc:15:24: error: extended character ¥ is not valid in an identifier
   15 |         cout << 909 << ¥n;
      |                        ^
a.cc:17:26: error: extended character ¥ is not valid in an identifier
   17 |         cout << N+910 << ¥n;
      |                          ^
a.cc:19:26: error: extended character ¥ is not valid in an identifier
   19 |         cout << 90909 << ¥n;
      |                          ^
a.cc: In function 'int main()':
a.cc:9:22: error: '\U000000a5n' was not declared in this scope
    9 |         cout << N << ¥n;
      |                      ^~
a.cc:11:22: error: '\U000000a5n' was not declared in this scope
   11 |         cout << 9 << ¥n;
      |                      ^~
a.cc:13:25: error: '\U000000a5n' was not declared in this scope
   13 |         cout << N+10 << ¥n;
      |                         ^~
a.cc:15:24: error: '\U000000a5n' was not declared in this scope
   15 |         cout << 909 << ¥n;
      |                        ^~
a.cc:17:26: error: '\U000000a5n' was not declared in this scope
   17 |         cout << N+910 << ¥n;
      |                          ^~
a.cc:19:26: error: '\U000000a5n' was not declared in this scope
   19 |         cout << 90909 << ¥n;
      |                          ^~
Language: C++

#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <numeric>
#include <math.h>

using namespace std;

typedef int long long;

const int q = 10000000000 + 7;

int main() {
	
	int n;
	cin >> n;
	int length = int(log10(n)) + 1;
	int s = 0;
	for (int i = 1; i < length; i++)
	{
		if (i % 2 != 0) {
			s += 9 * pow(10, i-1);
		}
	}
	if (length % 2 != 0) {
		s += n - pow(10, length - 1) + 1;
	}
	cout << s << endl;
	
	return 0;
}

Compiler output:
a.cc:10:18: error: declaration does not declare anything [-fpermissive]
   10 | typedef int long long;
      |                  ^~~~
a.cc:12:27: warning: overflow in conversion from 'long int' to 'int' changes value from '10000000007' to '1410065415' [-Woverflow]
   12 | const int q = 10000000000 + 7;
      |               ~~~~~~~~~~~~^~~
Language: C++

#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <numeric>

using namespace std;

typedef int long long;

const int q = 10000000000 + 7;

int main() {
	
	int n;
	cin >> n;
	int length = int(log10(n)) + 1;
	int s = 0;
	for (int i = 1; i < length; i++)
	{
		if (i % 2 != 0) {
			s += 9 * pow(10, i-1);
		}
	}
	if (length % 2 != 0) {
		s += n - pow(10, length - 1) + 1;
	}
	cout << s << endl;
	
	return 0;
}

Compiler output:
a.cc:9:18: error: declaration does not declare anything [-fpermissive]
    9 | typedef int long long;
      |                  ^~~~
a.cc:11:27: warning: overflow in conversion from 'long int' to 'int' changes value from '10000000007' to '1410065415' [-Woverflow]
   11 | const int q = 10000000000 + 7;
      |               ~~~~~~~~~~~~^~~
a.cc: In function 'int main()':
a.cc:17:26: error: 'log10' was not declared in this scope
   17 |         int length = int(log10(n)) + 1;
      |                          ^~~~~
a.cc:22:34: error: 'pow' was not declared in this scope
   22 |                         s += 9 * pow(10, i-1);
      |                                  ^~~
a.cc:26:26: error: 'pow' was not declared in this scope
   26 |                 s += n - pow(10, length - 1) + 1;
      |                          ^~~
Language: Java

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        int all = 0;
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        for (int i = 1; i <= n; i++) {
            String str = i + "";
            if (str.length() % 2 == 1) {
                all++;
            }
        }
        System.out.println(all + "");
    }
}

Compiler output:
Main.java:5: error: cannot find symbol
        Scanner sc = new Scanner(System.in);
        ^
  symbol:   class Scanner
  location: class Main
Main.java:5: error: cannot find symbol
        Scanner sc = new Scanner(System.in);
                         ^
  symbol:   class Scanner
  location: class Main
2 errors
Language: Java

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        int all = 0;
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        for (int i = 1; i <= n; i++) {
            String str = i + "";
            if (str.length() % == 1) {
                all++;
            }
        }
        System.out.println(all + "");
    }
}

Compiler output:
Main.java:9: error: illegal start of expression
            if (str.length() % == 1) {
                               ^
1 error
Language: C++

#include <iostream>

int main(int argc, char** argv)
{
    int N;
    std::cin >> N;

    int ans = 0;
    for (int i = N; i > 0; i--) {
        if (i < 10) ans++;
        else if (i < 100) ;
        else if (i < 1000) ans++;
        else if (i < 10000) ;
        else if (i < 100000) ans++;
        else 
    }

    std::cout << ans << std::endl;

    return 0;
}

Compiler output:
a.cc: In function 'int main(int, char**)':
a.cc:16:5: error: expected primary-expression before '}' token
   16 |     }
      |     ^
Language: C++

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    cin>>n;
    if(n<10) cout<<n;
    else if(n>=10 && n<100) cout<<"9";
    else if(n>=100 && n<1000) cout<<n-90;
    else if(n>=1000 && n<10000) cout<<"909";
    else if(n>=10000) && n<100000) cout<<n-9090;
    else cout<<"90909";
//    char a[10];
//    for(int i=0;i<10;i++) cin>>a[i];
//    sort(a,a+10);
//    for(int i=0;i<10;i++) cout<<a[i]<<" ";
//    int a,b,c;
//    cin>>a>>b>>c;
//    cout<<c-(a-b);
}


Compiler output:
a.cc: In function 'int main()':
a.cc:11:27: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   11 |     else if(n>=10000) && n<100000) cout<<n-9090;
      |                       ~~~~^~~~~~~
a.cc:11:34: error: expected ';' before ')' token
   11 |     else if(n>=10000) && n<100000) cout<<n-9090;
      |                                  ^
      |                                  ;
a.cc:11:26: error: label 'n' used but not defined
   11 |     else if(n>=10000) && n<100000) cout<<n-9090;
      |                          ^
Language: C++

#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;

int main() {
  int n,count=0; cin>>n;
  for(int i=0;i<n;i++) {
     if (int(log10(i))%2!=1) count++;
  }
  if(int(log10(n)%2==1) count++;
  cout << count << endl;
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:10:18: error: invalid operands of types '__gnu_cxx::__enable_if<true, double>::__type' {aka 'double'} and 'int' to binary 'operator%'
   10 |   if(int(log10(n)%2==1) count++;
      |          ~~~~~~~~^~
      |               |   |
      |               |   int
      |               __gnu_cxx::__enable_if<true, double>::__type {aka double}
a.cc:11:24: error: expected ')' before ';' token
   11 |   cout << count << endl;
      |                        ^
      |                        )
a.cc:10:5: note: to match this '('
   10 |   if(int(log10(n)%2==1) count++;
      |     ^
Language: C++

#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;

int main() {
  int n,count=0; cin>>n;
  for(int i=0;i<n;i++) {
     if (int(log10(i))%2!=1) count++;
  }
  if(int(log10(i)%2==1) count++;
  cout << count << endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:10:16: error: 'i' was not declared in this scope
   10 |   if(int(log10(i)%2==1) count++;
      |                ^
a.cc:11:24: error: expected ')' before ';' token
   11 |   cout << count << endl;
      |                        ^
      |                        )
a.cc:10:5: note: to match this '('
   10 |   if(int(log10(i)%2==1) count++;
      |     ^
Language: C++

    #include<bits/stdc++.h>
     
    using namespace std;
     
    int main(){
      int n,ans = 0;
      int keta = 0;
      cin >> n;
      
      while(n >= pow(10, keta)){
        keta++;
      }
      if(keta % 2 == 0){
        while(keta > 0){
          ans += 9 * (pow(10, keta));
          keta -= 2;
        }
      }
      
      else{
        ans += n-pow(10,keta));
        keta--;
        while(keta > 0){
          ans += 9 * (pow(10, keta));
          keta -= 2;
      }
      
      cout << ans << endl;
      return 0;
    }

Compiler output:
a.cc: In function 'int main()':
a.cc:21:30: error: expected ';' before ')' token
   21 |         ans += n-pow(10,keta));
      |                              ^
      |                              ;
a.cc:30:6: error: expected '}' at end of input
   30 |     }
      |      ^
a.cc:5:15: note: to match this '{'
    5 |     int main(){
      |               ^
Language: C++

#include<bits/stdc++.h>

using namespace std;

int main(){
  int n,ans = 0;
  int keta = 0;
  cin >> n;
  
  while(n >= pow(10, keta)){
    keta++;
  }
  if(keta % 2 == 0){
    while(keta > 0){
      ans += 9 * (pow(10, keta);
      keta -= 2;
    }
  }
  
  else{
    ans += n-pow(10,keta);
    keta--;
    while(keta > 0){
      ans += 9 * (pow(10, keta);
      keta -= 2;
  }
  
  cout << ans << endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:32: error: expected ')' before ';' token
   15 |       ans += 9 * (pow(10, keta);
      |                  ~             ^
      |                                )
a.cc:24:32: error: expected ')' before ';' token
   24 |       ans += 9 * (pow(10, keta);
      |                  ~             ^
      |                                )
a.cc:30:2: error: expected '}' at end of input
   30 | }
      |  ^
a.cc:5:11: note: to match this '{'
    5 | int main(){
      |           ^
Language: C++

#include <bits/stdc++.h>

using namespace std;

int ten(int n){
    int ret=1;
    for (int i = 0; i < n; ++i) {
        ret*=10;
    }
    return ret;
}

int main(){
    string n;
    cin>>n;
    int ans=0;
    int m=n.size();
    if(n.size()%2==1){
        ans+=stoi(n);
        string t=(m-1,'9');
        ans-=stoi(t);
        --m;
    }

    while(m>0){
        if(m%2==1)ans+=9*ten(m-1);
        --m;
    }
    cout<<ans<<endl;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:20:23: error: conversion from 'char' to non-scalar type 'std::string' {aka 'std::__cxx11::basic_string<char>'} requested
   20 |         string t=(m-1,'9');
      |                       ^~~
Language: C++

#include <bits/stdc++.h>

using namespace std;

int ten(int n){
    int ret=1;
    for (int i = 0; i < n; ++i) {
        ret*=10;
    }
    return ret;
}

int main(){
    string n;
    cin>>n;
    int ans=0;
    int m=n.size();
    if(n.size()%2==1){
        ans+=stoi(n);
        string(m-1,'9');
        ans-=stoi(t);
        --m;
    }

    while(m>0){
        if(m%2==1)ans+=9*ten(m-1);
        --m;
    }
    cout<<ans<<endl;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:21:19: error: 't' was not declared in this scope
   21 |         ans-=stoi(t);
      |                   ^
Language: C++

#include <bits/stdc++.h>

using namespace std;

int ten(int n){
    int ret=1;
    for (int i = 0; i < n; ++i) {
        ret*=10;
    }
    return ret;
}

int main(){
    string n;
    cin>>n;
    int ans=0;
    int m=n.size();
    if(n.size()%2==1){
        ans+=stoi(n);
        string(m-1,'9')
        ans-=stoi(t);
        --m;
    }

    while(m>0){
        if(m%2==1)ans+=9*ten(m-1);
        --m;
    }
    cout<<ans<<endl;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:20:24: error: expected ';' before 'ans'
   20 |         string(m-1,'9')
      |                        ^
      |                        ;
   21 |         ans-=stoi(t);
      |         ~~~
Language: C++

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

int main() {
  int n;
  cin >> n;
  ans = 0;
  for (int i = 1; i <= n; ++i) {
    int s = to_string(i);
    if (s.size() % 2 == 1) {
      ++ans;
    }
  }
  cout << ans << endl;
  return 0;
}
      

Compiler output:
a.cc: In function 'int main()':
a.cc:8:3: error: 'ans' was not declared in this scope; did you mean 'abs'?
    8 |   ans = 0;
      |   ^~~
      |   abs
a.cc:10:22: error: cannot convert 'std::string' {aka 'std::__cxx11::basic_string<char>'} to 'int' in initialization
   10 |     int s = to_string(i);
      |             ~~~~~~~~~^~~
      |                      |
      |                      std::string {aka std::__cxx11::basic_string<char>}
a.cc:11:11: error: request for member 'size' in 's', which is of non-class type 'int'
   11 |     if (s.size() % 2 == 1) {
      |           ^~~~
Language: C++

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

int main(){
  int N; cin >> N;
  int ans = 0;
  int digit = 0;
  for(int i=1; i<=N; i++){
    digit =0;
    int a=i;
    while(a!=0){
      digit++;
      a/=(10);
      }
    }
    if(digit%2 == 1){
      ans++;
    }
  }
  cout << ans << endl;
}


Compiler output:
a.cc:20:3: error: 'cout' does not name a type
   20 |   cout << ans << endl;
      |   ^~~~
a.cc:21:1: error: expected declaration before '}' token
   21 | }
      | ^
Language: C++

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

int main(){
  int N; cin >> N;
  int ans = 0;
  int digit = 0;
  for(int i=1; i<=N; i++){
    int a=i;
    while(a!=0)
      digit =0;
      digit++;
      a/10;
    }
    if(digit%2 == 1){
      ans++;
    }
  }
  cout << ans << endl;
}

    
  


Compiler output:
a.cc:19:3: error: 'cout' does not name a type
   19 |   cout << ans << endl;
      |   ^~~~
a.cc:20:1: error: expected declaration before '}' token
   20 | }
      | ^
Language: C++

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

int main(){
  int N; cin >> N;
  int ans = 0;
  for(int i=1; i<=N; i++){
    int a=i;
    while(a!=0){
      int digit = 0;
      digit++;
      a/10;
    }
    if(digit%2 == 1){
      ans++;
    }
  }
  cout << ans << endl;
}

    
  

Compiler output:
a.cc: In function 'int main()':
a.cc:14:8: error: 'digit' was not declared in this scope
   14 |     if(digit%2 == 1){
      |        ^~~~~
Language: Java

import java.util.Scanner;
public class main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc=new Scanner(System.in);
		int a=sc.nextInt();
		int c=0;
		for(int i=1;i<=a;i++) {
			String s=String.valueOf(i);
			if(s.length()%2==1) {
				c++;
			}
		}
		System.out.print(c);

	}

}

Compiler output:
Main.java:2: error: class main is public, should be declared in a file named main.java
public class main {
       ^
1 error
Language: C++

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

bool f(int x){
  int keta = 0;
  while(x>0){
    keta++;
    x /= 10; // 110/10=11 11/10=1 1/10=0 これでketaが3となっている
  }
  return keta%2 == 1;　//奇数の場合、1なので、真が返り値となる（bool）
}

int main(){
  int n;
  cin >> n;
  int ans = 0;
  for(int i =1; i<=n; i++){
    if(f(i)){ //f(i)は偶数奇数を判定する関数（iが奇数の場合、ansをインクリメント）
      ans++;
    }
  }
  cout << ans << endl;
}


Compiler output:
a.cc:10:22: error: extended character 　 is not valid in an identifier
   10 |   return keta%2 == 1;　//奇数の場合、1なので、真が返り値となる（bool）
      |                      ^
a.cc: In function 'bool f(int)':
a.cc:10:22: error: '\U00003000' was not declared in this scope
   10 |   return keta%2 == 1;　//奇数の場合、1なので、真が返り値となる（bool）
      |                      ^~
Language: C++

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

int main(){
int n;
cin>>n;
if(n<10){
  cout<<n<<endl;
}
else if(10<=n&&n<100){
  cout<<9<<endl;
}
else if(100<=n&&n<1000){
  cout<<n-90<<endl;
}
else if(1000<=n&&n<10000){
  cout<<909<<endl;
}
else if(10000<=n&&n<100000){
  cout<<n-9090<<endl;
}
else if(n=100000){
  cout<90909<<endl;
}
  return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:23:13: error: invalid operands of types 'int' and '<unresolved overloaded function type>' to binary 'operator<<'
   23 |   cout<90909<<endl;
      |        ~~~~~^~~~~~
Language: C

#include<stdio.h>
int main(void){
  int n;
  scanf("%d",%n);
  if(n<10){
    printf("%d",n);
  }else if(n<100){
    printf("%d",9);
  }else if(n<1000){
    printf("%d",n-90);
  }else if(n<10000){
    printf("%d",909);
  }else if(n<100000){
    printf("%d",n-9090);
  }else{
    printf("%d",90909);
  }
  return 0;
}

Compiler output:
main.c: In function 'main':
main.c:4:14: error: expected expression before '%' token
    4 |   scanf("%d",%n);
      |              ^
Language: C++

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

int main(){
    int N;
    cin >> N;
    int count = 0;

    for (int i = 0;i <= N;i++){
        if (i.size() % 2 != 0){
            count++;
        }
    }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:10:15: error: request for member 'size' in 'i', which is of non-class type 'int'
   10 |         if (i.size() % 2 != 0){
      |               ^~~~
Language: C++

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

int main(){
    int N;
    cin >> N;
    int count = 0;

    for (int i = 0;i < N;i++){
        if (N.size() % 2 != 0){
            count++;
        }
    }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:10:15: error: request for member 'size' in 'N', which is of non-class type 'int'
   10 |         if (N.size() % 2 != 0){
      |               ^~~~
Language: C++

#include<bits/stdc++.h>
using namespace std;
#define ALL(v) (v).begin(),(v).end()
#define REP(i,p,n) for(int i=p;i<(int)(n);++i)
#define rep(i,n) REP(i,0,n)
#define SZ(x) ((int)(x).size())
#define INF 999999999
typedef long long int Int;
using ll = long long;
using VI = vector<int>;
int gcd(Int a, Int b) {
 return b != 0 ? gcd(b, a % b) : a;
}
int lcm(Int a, Int b) {
 return a / gcd(a, b)*b;
}
int main(){
  int n;cin >> n;
  int ans = 0;
  rep(i,n){
    if((log10(i)+1)%2==1) ans++;
  }
  cout << ans << endl;
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:21:20: error: invalid operands of types '__gnu_cxx::__enable_if<true, double>::__type' {aka 'double'} and 'int' to binary 'operator%'
   21 |     if((log10(i)+1)%2==1) ans++;
      |        ~~~~~~~~~~~~^~
      |                 |   |
      |                 |   int
      |                 __gnu_cxx::__enable_if<true, double>::__type {aka double}
Language: C++

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

int main(){
    int n;
    cin>> n;
    
    int answer;
    for(int i = 0; i < 6; i++{
        if(n >= pow(10, i) && n < pow(10, i + 1)){
            switch(i){
                case 0:
                    answer = n;
                    break;
                case 1:
                    answer = 9;
                    break;
                case 2:
                    answer = 9 + n - 99;
                case 3:
                    answer = 909;
                case 4:
                    answer = 909 + n - 9999;
                case 5:
                    answer = 90909;
            }
        }
    }
    
    cout << answer << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:30: error: expected ')' before '{' token
    9 |     for(int i = 0; i < 6; i++{
      |        ~                     ^
      |                              )
Language: C++


#include <iostream>
#include<iomanip>
#include <iomanip>
//#include <math.h>

using namespace std;

void A(),B(),C(),D(),E();
bool subC(int*, int);

int main()
{
	B();
}
void C() {
	int N; cin >> N;
	int* H = new int[N];
	for (int i = 0; i < N; i++) cin >> H[i];

	if (subC(H, N)) cout << "Yes" << endl;
	else cout << "No" << endl;

	delete[] H;
}
bool subC(int* H, int len) {
	int tempMax = 0;
	for (int i = 0; i < len - 1; i++) {
		tempMax = fmax(tempMax, H[i]);
		if (tempMax >= H[i + 1] + 2) return false;
	}
	return true;
}

void B() {
	int N; 
	cin >> N;
	int M = (N + 1) / 2;
	cout << M << endl;


}

Compiler output:
a.cc: In function 'bool subC(int*, int)':
a.cc:29:27: error: 'fmax' was not declared in this scope
   29 |                 tempMax = fmax(tempMax, H[i]);
      |                           ^~~~
Language: C++


#include <iostream>
#include<iomanip>
#include <iomanip>
//#include <math.h>

using namespace std;

void A(),B(),C(),D(),E();
bool subC(int*, int);

int main()
{
	B();
}
void C() {
	int N; cin >> N;
	int* H = new int[N];
	for (int i = 0; i < N; i++) cin >> H[i];

	if (subC(H, N)) cout << "Yes" << endl;
	else cout << "No" << endl;

	delete[] H;
}
bool subC(int* H, int len) {
	int tempMax = 0;
	for (int i = 0; i < len - 1; i++) {
		tempMax = fmax(tempMax, H[i]);
		if (tempMax >= H[i + 1] + 2) return false;
	}
	return true;
}

void B() {
	int N; 
	cin >> N;
	cout << N / 2 << endl;


}

Compiler output:
a.cc: In function 'bool subC(int*, int)':
a.cc:29:27: error: 'fmax' was not declared in this scope
   29 |                 tempMax = fmax(tempMax, H[i]);
      |                           ^~~~
Language: C++

#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <unordered_map>

using namespace std;
int main(){
    int N;
    int ans;
    cin >> N;
    if(N/100000 == 1){
        ans = 90909;
    }else if(N/10000 > 0){
        ans = 909 + (1000*((N/1000)-1))+ N%10000 + 1;
    }else if(N/1000 > 0){
        ans = 909;
    }else if(N/100 > 0){
        ans = 9 + (100*((N/100)-1))+N%100 + 1;
    }else if(N/10 > 0){
        ans = 9;
    }else{
        ans = N;
    }
    cout << ans << endl;

Compiler output:
a.cc: In function 'int main()':
a.cc:25:25: error: expected '}' at end of input
   25 |     cout << ans << endl;
      |                         ^
a.cc:8:11: note: to match this '{'
    8 | int main(){
      |           ^
Language: C++

#include<iostream>
#include<cmath>
using namespace std;
int main() {
	long long N,t=0,P,sum=0;
	cin >> N;
	P = N;
	do {
		t++;
		P/=10;
	} while (P);
	for (int i = 1; i <= t; i += 2)
	{
		if (i == t)
		sum +=long long( N - pow(10, (t - 1))+1);
		else
		sum +=long long( pow(10, i) - pow(10, (i - 1)));
	}
	cout << sum;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:23: error: expected primary-expression before 'long'
   15 |                 sum +=long long( N - pow(10, (t - 1))+1);
      |                       ^~~~
a.cc:17:23: error: expected primary-expression before 'long'
   17 |                 sum +=long long( pow(10, i) - pow(10, (i - 1)));
      |                       ^~~~
Language: C++

#include<iostream>
using namespace std;
int main() {
	int N,t=0,P,sum=0;
	cin >> N;
	P = N;
	do {
		t++;
		P/=10;
	} while (P);
	for (int i = 1; i <= t; i += 2)
	{
		if (i == t)
		sum += N - pow(10, (t - 1))+1;
		else
		sum += pow(10, i) - pow(10, (i - 1));
	}
	cout << int(sum);
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:14:28: error: 'pow' was not declared in this scope
   14 |                 sum += N - pow(10, (t - 1))+1;
      |                            ^~~
a.cc:16:24: error: 'pow' was not declared in this scope
   16 |                 sum += pow(10, i) - pow(10, (i - 1));
      |                        ^~~
Language: C++

using namespace std;
int main()
{
    int n;
    cin >> n;
  int ans;
  if(n==100000) ans=90909;
  else if(n>=10000) ans=9+900+n-10000+1;
  else if(n>=1000) ans=9+900;
  else if(n>=100) ans=9+n-100+1;
  else if(n>=10) ans=9;
  else ans=n;
  cout << ans << endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:5: error: 'cin' was not declared in this scope
    5 |     cin >> n;
      |     ^~~
a.cc:1:1: note: 'std::cin' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
  +++ |+#include <iostream>
    1 | using namespace std;
a.cc:13:3: error: 'cout' was not declared in this scope
   13 |   cout << ans << endl;
      |   ^~~~
a.cc:13:3: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:13:18: error: 'endl' was not declared in this scope
   13 |   cout << ans << endl;
      |                  ^~~~
a.cc:1:1: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
  +++ |+#include <ostream>
    1 | using namespace std;
Language: Java

import java.util.*;

class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        if(n <= 9) System.out.println(n);
        else if(n <= 99)System.out.println(9);
        else if(n <= 999)System.out.println(n-90);
        else if(n <= 9999)System.out.println(909);
        else if(n <= 99999)System.out.println(n-9090);
        els System.out.println(90909);
    }
}

Compiler output:
Main.java:12: error: ';' expected
        els System.out.println(90909);
                  ^
1 error
Language: C++

#include <bits/stdc++.h>
#define speed                                                                  \
  ios_base::sync_with_stdio(0);                                                \
  cin.tie(0);                                                                  \
  cout.tie(0);
#define oprecision                                                             \
  cout.precision(30);                                                          \
  cerr.precision(7);
#define bb bool
#define ii int
#define ll long long
#define ff float
#define dd double
#define cc char
#define ss string
#define forn(sz) for (int i = 1; i <= sz; i++)
#define forni(i, sz) for (int i = 1; i <= sz; i++)
#define fornid(i, m, sz) for (int i = m; i <= sz; i++)
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define vii vector<ii>
#define vii64 vector<ll>
#define vb vector<bb>
using namespace std;
int con(int a) return (to_string(a).size() % 2 == 1);
ii a, cnt;
ii main() {
  speed;
  oprecision;
  /*#ifndef ONLINE_JUDGE
    freopen("outd.txt", "rt", stdin);
  #endif*/
  // code
  cin >> a;
  forn(a) {
    if (con(i))
      cnt++;
  }
  cout << cnt;
  // endl
#ifndef ONLINE_JUDGE
  cerr << "\nTime elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
#endif
  return 0;
}


Compiler output:
a.cc: In function 'int con(int)':
a.cc:26:23: error: expected identifier before '(' token
   26 | int con(int a) return (to_string(a).size() % 2 == 1);
      |                       ^
a.cc:26:16: error: named return values are no longer supported
   26 | int con(int a) return (to_string(a).size() % 2 == 1);
      |                ^~~~~~
a.cc:38:7: error: 'cnt' was not declared in this scope; did you mean 'int'?
   38 |       cnt++;
      |       ^~~
      |       int
a.cc:40:11: error: 'cnt' was not declared in this scope; did you mean 'int'?
   40 |   cout << cnt;
      |           ^~~
      |           int
Language: C++

include <iostream>
using namespace std;
int main()
{
  int n,keta,ans=0;
  cin>>n;
  for(int i=0;i<=5;i++) if(n>=pow(10,i)) keta=i+1;
  for(int i=1;i<keta;i++) if(i%2==1) ans+=9*pow(10,i-1);
  if(keta%2==1) ans+=n-pow(10,keta-1)+1;
  cout>>ans;
}

Compiler output:
a.cc:1:1: error: 'include' does not name a type
    1 | include <iostream>
      | ^~~~~~~
a.cc: In function 'int main()':
a.cc:6:3: error: 'cin' was not declared in this scope
    6 |   cin>>n;
      |   ^~~
a.cc:7:31: error: 'pow' was not declared in this scope
    7 |   for(int i=0;i<=5;i++) if(n>=pow(10,i)) keta=i+1;
      |                               ^~~
a.cc:8:45: error: 'pow' was not declared in this scope
    8 |   for(int i=1;i<keta;i++) if(i%2==1) ans+=9*pow(10,i-1);
      |                                             ^~~
a.cc:9:24: error: 'pow' was not declared in this scope
    9 |   if(keta%2==1) ans+=n-pow(10,keta-1)+1;
      |                        ^~~
a.cc:10:3: error: 'cout' was not declared in this scope
   10 |   cout>>ans;
      |   ^~~~
Language: C++

#include<bits/stdc++.h>
using namespace std;
int main(){
  int N;
  cin >> N;
  int c = 0;
  while(1 <= N){
    if(10*10*10*10 <= N && N < 10*10*10*10*10;){
      c++;
    }
    else if(10*10 <= N && N < 10*10*10;){
      c++;
    }
    else if(1<= N && N < 10;){
      c++;
    }
    N--;
  }
  cout << c <<endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:8:47: error: expected primary-expression before ')' token
    8 |     if(10*10*10*10 <= N && N < 10*10*10*10*10;){
      |                                               ^
a.cc:11:40: error: expected primary-expression before ')' token
   11 |     else if(10*10 <= N && N < 10*10*10;){
      |                                        ^
a.cc:14:29: error: expected primary-expression before ')' token
   14 |     else if(1<= N && N < 10;){
      |                             ^
Language: C++

#include<string>
using namespace std;

main(){
  int i,n,sum=0;
  cin >> n;
  
  for(i=1;i<=n;i++){ 
  	size_t size = to_string(i).length();
    if (size%2==1){
      sum++;
    }
  }
  cout << sum << endl;
}
  


Compiler output:
a.cc:4:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
    4 | main(){
      | ^~~~
a.cc: In function 'int main()':
a.cc:6:3: error: 'cin' was not declared in this scope
    6 |   cin >> n;
      |   ^~~
a.cc:2:1: note: 'std::cin' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
    1 | #include<string>
  +++ |+#include <iostream>
    2 | using namespace std;
a.cc:14:3: error: 'cout' was not declared in this scope
   14 |   cout << sum << endl;
      |   ^~~~
a.cc:14:3: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:14:18: error: 'endl' was not declared in this scope
   14 |   cout << sum << endl;
      |                  ^~~~
a.cc:2:1: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
    1 | #include<string>
  +++ |+#include <ostream>
    2 | using namespace std;
Language: C++

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

main(){
  int i,sum=0;
  string n;
  cin >> n;
  
  for(i=0;i<=100000;i++){
    if(length(n%2==1)){
      sum++;
    }
  }
  cout << sum << endl;
}
  
  

Compiler output:
a.cc:5:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
    5 | main(){
      | ^~~~
a.cc: In function 'int main()':
a.cc:11:16: error: no match for 'operator%' (operand types are 'std::string' {aka 'std::__cxx11::basic_string<char>'} and 'int')
   11 |     if(length(n%2==1)){
      |               ~^~
      |               | |
      |               | int
      |               std::string {aka std::__cxx11::basic_string<char>}
a.cc:11:8: error: 'length' was not declared in this scope
   11 |     if(length(n%2==1)){
      |        ^~~~~~
Language: C++

#include <iostream>
#include <string>

int main(){
  int n,ans=0;
  cin >> n;
  string str=to_string(n);
  for(int i=0;i<n;i++){
    if(str.length()%2==1)ans++;
  }
  cout<<ans;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:6:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |   cin >> n;
      |   ^~~
      |   std::cin
In file included from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:7:3: error: 'string' was not declared in this scope
    7 |   string str=to_string(n);
      |   ^~~~~~
a.cc:7:3: note: suggested alternatives:
In file included from /usr/include/c++/14/iosfwd:41,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
In file included 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:
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:9:8: error: 'str' was not declared in this scope; did you mean 'std'?
    9 |     if(str.length()%2==1)ans++;
      |        ^~~
      |        std
a.cc:11:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   11 |   cout<<ans;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
Language: C++

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

int main() {
  string n;
  cin>>n;
  if(n.size()==1){
    cout<<n.size()-1<<endl;
  }
  else if(n.size()==2){
    cout<<"9"<<endl;
  }
  else if(s.size()==3){
    cout<<s.size()-90<<endl;
  }
  else if(s.size()==4){
    cout<<"909"<<endl;
  }
  else if(s.size()==5){
    cout<<s.size()-9090<<endl;
  }
  else{
    cout<<"90909"<<endl;
  }
  
}

Compiler output:
a.cc: In function 'int main()':
a.cc:13:11: error: 's' was not declared in this scope
   13 |   else if(s.size()==3){
      |           ^
Language: C

#include<stdio.h>
int main()
{
  int n;
  scanf("%d",&n);
  int i,j,k=0,m=0;
  for(i=1;i<=n;i++)
  {
    j=i;
    while(j!=0)
    {
      k++;
      j=j/10;
    }
      if(k%2!=0)
      m++;
  }
  printf("%d",m);
  return 0;

Compiler output:
main.c: In function 'main':
main.c:19:3: error: expected declaration or statement at end of input
   19 |   return 0;
      |   ^~~~~~
Language: C

include<stdio.h>
int main()
{
  int n;
  scanf("%d",&n);
  int i,j,k=0,m=0;
  for(i=1;i<=n;i++)
  {
    j=i;
    while(j!=0)
    {
      k++;
      j=j/10;
    }
      if(k%2!=0)
      m++;
  }
  printf("%d",m);
  return 0;
}

Compiler output:
main.c:1:8: error: expected '=', ',', ';', 'asm' or '__attribute__' before '<' token
    1 | include<stdio.h>
      |        ^
Language: C++

using namespace std;

int main() {
	int a;
  	int count=0;
  	cin >> a;
  	for(int i=1;i < a+1;i++){
      if(i/10 ==0)
        count++;
  	  else if(i/100 >= 1 && i/100 < 10)
        		count++;
      		else if(i/10000 >= 1&&i/10000 <10)
        			count++;
    }
  cout << count;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:6:9: error: 'cin' was not declared in this scope
    6 |         cin >> a;
      |         ^~~
a.cc:1:1: note: 'std::cin' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
  +++ |+#include <iostream>
    1 | using namespace std;
a.cc:15:3: error: 'cout' was not declared in this scope
   15 |   cout << count;
      |   ^~~~
a.cc:15:3: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
Language: C

#include<stdio.h>
int main()
{
  int n;
  scanf("%d",&n);
  int i,j=0;
  for(i=1;i<=n;i++)
  {
    if(i%10!=0)
      j++;
  }
  printf("%d",j);
  retunr 0;
}
      

Compiler output:
main.c: In function 'main':
main.c:13:3: error: 'retunr' undeclared (first use in this function)
   13 |   retunr 0;
      |   ^~~~~~
main.c:13:3: note: each undeclared identifier is reported only once for each function it appears in
main.c:13:9: error: expected ';' before numeric constant
   13 |   retunr 0;
      |         ^~
      |         ;
Language: C++

#include <bits/stdc++.h>
using namespace std;
int main(){
  int N, ans;
  cin >> N;
  // num of 1~9 + 100~999 + 10000~99999
  ans = min(9,n) + min(900, max(0, n -99)) + min(90000, max(0, n -9999));
  cout << ans << endl;                                       
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:15: error: 'n' was not declared in this scope
    7 |   ans = min(9,n) + min(900, max(0, n -99)) + min(90000, max(0, n -9999));
      |               ^
Language: C++

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

bool f(int x){
  int keta=0;
  while(x){
    x/=10;
    keta++;
  }
}

int main(){
  
  int n;
  cin >> n;
  
  int ans=0;
  for(int i=0;i<n;i++){
    if(f(i)%2==1) ans++;
  }

Compiler output:
a.cc: In function 'bool f(int)':
a.cc:10:1: warning: no return statement in function returning non-void [-Wreturn-type]
   10 | }
      | ^
a.cc: In function 'int main()':
a.cc:20:4: error: expected '}' at end of input
   20 |   }
      |    ^
a.cc:12:11: note: to match this '{'
   12 | int main(){
      |           ^
Language: C++

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

bool f(int x);{
  int keta=0;
  while(x){
    x/=10;
    keta++;
  }
}

int main(){
  
  int n;
  cin >> n;
  
  int ans=0;
  for(int i=0;i<n;i++){
    if(f(i)%2==1) ans++;
  }

Compiler output:
a.cc:4:15: error: expected unqualified-id before '{' token
    4 | bool f(int x);{
      |               ^
a.cc: In function 'int main()':
a.cc:20:4: error: expected '}' at end of input
   20 |   }
      |    ^
a.cc:12:11: note: to match this '{'
   12 | int main(){
      |           ^
Language: C++

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

int main(){
  bool f=0;
  while(x){
    n/=10;
    f++;
  }
  
  int n;
  cin >> n;
  
  int ans=0;
  for(int i=0;i<n;i++){
    if(f%2==1) ans++;
  }

Compiler output:
a.cc: In function 'int main()':
a.cc:6:9: error: 'x' was not declared in this scope
    6 |   while(x){
      |         ^
a.cc:7:5: error: 'n' was not declared in this scope
    7 |     n/=10;
      |     ^
a.cc:8:5: error: use of an operand of type 'bool' in 'operator++' is forbidden in C++17
    8 |     f++;
      |     ^
a.cc:17:4: error: expected '}' at end of input
   17 |   }
      |    ^
a.cc:4:11: note: to match this '{'
    4 | int main(){
      |           ^
Language: C++

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

bool f=0;
  while(x){
    n/=10;
    f++;
  }
int main(){
  int n;
  cin >> n;
  
  int ans=0;
  for(int i=0;i<n;i++){
    if(f%2==1) ans++;
  }

Compiler output:
a.cc:5:3: error: expected unqualified-id before 'while'
    5 |   while(x){
      |   ^~~~~
a.cc: In function 'int main()':
a.cc:16:4: error: expected '}' at end of input
   16 |   }
      |    ^
a.cc:9:11: note: to match this '{'
    9 | int main(){
      |           ^
Language: C++

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

bool f=0
  while(x){
    n/=10;
    f++;
  }
int main(){
  int n;
  cin >> n;
  
  int ans=0;
  for(int i=0;i<n;i++){
    if(f%2==1) ans++;
  }

Compiler output:
a.cc:5:3: error: expected ',' or ';' before 'while'
    5 |   while(x){
      |   ^~~~~
a.cc: In function 'int main()':
a.cc:16:4: error: expected '}' at end of input
   16 |   }
      |    ^
a.cc:9:11: note: to match this '{'
    9 | int main(){
      |           ^
Language: C++

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

bool f(i)=0
  while(x){
    n/=10;
    f(i)++;
  }
int main(){
  int n;
  cin >> n;
  
  int ans=0;
  for(int i=0;i<n;i++){
    if(f(i)%2==1) ans++;
  }

Compiler output:
a.cc:4:8: error: 'i' was not declared in this scope
    4 | bool f(i)=0
      |        ^
a.cc: In function 'int main()':
a.cc:15:9: error: 'f' cannot be used as a function
   15 |     if(f(i)%2==1) ans++;
      |        ~^~~
a.cc:16:4: error: expected '}' at end of input
   16 |   }
      |    ^
a.cc:9:11: note: to match this '{'
    9 | int main(){
      |           ^
Language: C

#include <stdio.h>
 
int main()
{
	  
   int N;
   Int Ans;
   
    scanf("%d", &N);
    if(N> 100000) N=100000; 
    if(N<1) N=1;

   
    if(N=100000) Ans = 9 + (100*9) + (10000*9); // 90909
    else if(N >= 10000){
        Ans = 9 + 900 + N%10000 + 1;
    }
    else if(N>=100){
        Ans = 9 + N%100 + 1;
    }

  　printf("%d",C);
    
  
  return 0;
   
}

Compiler output:
main.c: In function 'main':
main.c:7:4: error: unknown type name 'Int'; did you mean 'int'?
    7 |    Int Ans;
      |    ^~~
      |    int
main.c:22:3: error: stray '\343' in program
   22 |   <U+3000>printf("%d",C);
      |   ^~~~~~~~
main.c:22:17: error: 'C' undeclared (first use in this function)
   22 |   　printf("%d",C);
      |                 ^
main.c:22:17: note: each undeclared identifier is reported only once for each function it appears in
Language: C++

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

shiguma(int a,int b){
  int c=b-a+1;
  return c;
}
int main(){
  int N;
  cin>>N;

  int a=1;
  int b=9;
  int ans=0;
  bool check=1;
  while(check){
    if(a<=N){
      if(b<N){
        ans+=shiguma(a,b);
      }else{
        ans+=shiguma(a,N);
        check=0;
      }
    }else{
      check=0;
    }
    a*=100;
    b=b*100+99;
  }
  cout<<ans<<endl;


}


Compiler output:
a.cc:4:1: error: ISO C++ forbids declaration of 'shiguma' with no type [-fpermissive]
    4 | shiguma(int a,int b){
      | ^~~~~~~
Language: C++

#include <bits/stdc++.h>

using namespace std;



int main() {
	
  int N,count;cin >> N;
  count = 0;
  string s;
  for(int i=1;i<=N,i++){
    s = to_string(N);
    int leng = s.length();
    if(leng%2==1) count++;
  }
  cout << count;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:12:23: error: expected ';' before ')' token
   12 |   for(int i=1;i<=N,i++){
      |                       ^
      |                       ;
Language: C++

#include <bits/stdc++.h>

using namespace std;



int main() {
	
  int N,count;cin >> N;
  count = 0;
  string s;
  for(i=1;i<=N,i++){
    s = to_string(N);
    int leng = s.length();
    if(leng%2=1) count++;
  }
  cout << count;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:12:7: error: 'i' was not declared in this scope
   12 |   for(i=1;i<=N,i++){
      |       ^
a.cc:12:19: error: expected ';' before ')' token
   12 |   for(i=1;i<=N,i++){
      |                   ^
      |                   ;
a.cc:15:12: error: lvalue required as left operand of assignment
   15 |     if(leng%2=1) count++;
      |        ~~~~^~
Language: C++

#include<iostream>
using namespace std

int main(){
    int N,a;
    cin>>N;
    a = min(9,N)+min(900,max(0,N-99))+min(90000,max(0,N-9999));
    cout<<a;
return 0;
}

Compiler output:
a.cc:2:20: error: expected ';' before 'int'
    2 | using namespace std
      |                    ^
      |                    ;
    3 | 
    4 | int main(){
      | ~~~
Language: C++

#include<iostream>
using namspace std

int main(){
    int N;
    cin>>N;
    a = min(9,N)+min(900,max(0,N-99))+min(90000,max(0,N-9999));
    cout<<a;
return 0;
}

Compiler output:
a.cc:2:7: error: expected nested-name-specifier before 'namspace'
    2 | using namspace std
      |       ^~~~~~~~
Language: C++

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





int main() {
	int N; cin >> N;
	int ans = 0;
	
	for (int i = 1;i <= N;i++) {
		int digit = 0;
		while (i) {
			i %= 10;
			digit++;

		}
		if (digit % 2 != 0) {
			ans++;
		}

	}
	cout << ans << endl;
}

Compiler output:
a.cc:1:1: error: 'include' does not name a type
    1 | include<bits/stdc++.h>
      | ^~~~~~~
a.cc: In function 'int main()':
a.cc:9:16: error: 'cin' was not declared in this scope
    9 |         int N; cin >> N;
      |                ^~~
a.cc:24:9: error: 'cout' was not declared in this scope
   24 |         cout << ans << endl;
      |         ^~~~
a.cc:24:24: error: 'endl' was not declared in this scope
   24 |         cout << ans << endl;
      |                        ^~~~
Language: C++

#include <iostream>
#include <cmath>
using namespace std;
int main() {
 int n; cin >> n;
 int tot = 0;
 for (int i = 1; i <= n; i++) {
  int d = 0;
  int j = i;
   while (j > 0) {
    d++;
    j /= 10;
   }
   tot += d % 2;
 }

Compiler output:
a.cc: In function 'int main()':
a.cc:15:3: error: expected '}' at end of input
   15 |  }
      |   ^
a.cc:4:12: note: to match this '{'
    4 | int main() {
      |            ^
Language: C++

#include <bits/stdc++.h>
using namespace std;
int main(){
  int count = 0;
  for (int i=1;i<=n;i++){
    if (to_string(n).length()%2 == 1){
      count++;
    }
  }
  cout << count << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:5:19: error: 'n' was not declared in this scope
    5 |   for (int i=1;i<=n;i++){
      |                   ^
Language: Java

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
public class Main
{
  
  public static void main(String[] args)
  {
    BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
    int N=Integer.parseInt(br.readLine());
    int ans=0;
    if(N<100){
      ans=Math.min(N,9);
    }else if (N<10000){
      ans=10+Math.min(N-99,900);
    }else{
      ans=10+900+Math.min(N-9999,90000);
    }
    System.out.println(ans);
  }
}


Compiler output:
Main.java:10: error: unreported exception IOException; must be caught or declared to be thrown
    int N=Integer.parseInt(br.readLine());
                                      ^
1 error
Language: C++

#include <iostream>
5 
using namespace std;

int main (void)
{
  int n;
  
  cin >> n;
  
  int sub = 0;
  if (n > 100) sub += 90;
  if (n > 10000) sub += 9000;
  
  cout << (n - sub) << endl;
  
  return 0; 
}

Compiler output:
a.cc:2:1: error: expected unqualified-id before numeric constant
    2 | 5
      | ^
a.cc: In function 'int main()':
a.cc:9:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    9 |   cin >> n;
      |   ^~~
      |   std::cin
In file included from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:15:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   15 |   cout << (n - sub) << endl;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:15:24: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   15 |   cout << (n - sub) << endl;
      |                        ^~~~
      |                        std::endl
In file included from /usr/include/c++/14/iostream:41:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
Language: C++

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

int main() {
  int N;
  cin >> N ;
  if(1 <= N <10){
    cout << N << endl;
  }
  else if (10 <= N < 100){
    cout << 9 << endl;
  }
  else if (100 <= N < 1000){
    cout << 9 + N - 99<<endl;
  }
  else if (1000 <= < 10000){
    cout << 909 << endl;
  }
  else{
    cout << 909 + N - 9999<<endl;
  }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:16:20: error: expected primary-expression before '<' token
   16 |   else if (1000 <= < 10000){
      |                    ^
Language: C++

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

int main() {
  int N;
  cin >> N ;
  if(1 <= N <10){
    cout << N << endl;
  }
  else if (10 <= N < 100){
    cout << 9 << endl;
  }
  else if (100<=N<1000){
    cout << 9 + N - 99<<endl;
  }
  else if (1000=<N<10000){
    cout << 909 << endl;
  }
  else{
    cout << 909 + N - 9999<<endl;
  }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:16:17: error: expected primary-expression before '<' token
   16 |   else if (1000=<N<10000){
      |                 ^