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

///package CodeChef;


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Main {
   public static int mod=1000000007;
   public static int minPlus=mod;
	public static void main(String[] ard)  throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		PrintWriter pw=new PrintWriter(System.out);
		String[] s=br.readLine().trim().split("\\s++");
		int S=Integer.valueOf(s[0]);
		int A=Integer.valueOf(s[1]);
		int B=Integer.valueOf(s[2]);
		if(Math.abs(A-S)<Math.abs(S-B))pw.println("A");
		else pw.println("B");
		pw.close();
	}
	public  static void go (String num, String s, int sum, int i) {
	    if (i>=num.length()) {
	      int t = 0;
	      long rs = 0;
	      StringTokenizer st = new StringTokenizer(s,"+");
	      t = st.countTokens();
	      while (st.hasMoreTokens()) {
	        rs+=Long.parseLong((String)st.nextToken());
	      }
	      if (rs == sum) minPlus = Math.min(minPlus,t);
	    } else {
	      if (i == 0) go (num,""+num.charAt(i), sum, i+1);
	      else {
	        go (num,s+"+"+num.charAt(i),sum,i+1);
	        go (num,s+num.charAt(i),sum,i+1);
	      }
	 
	    }
	        
	 
	  }
	public static int pa(int n)
	{     int a=0;
	      int b=0;
		
		if(n<=0)return 1;
		System.out.println("kumar");
		 a+=pa(n-1);
		 System.out.println("prabhat");  
		 b+=pa(n-1);
		//System.out.println( callme("vikrant"));
	   
		return a+b;
	}
	public static  String callme(String s)
	{
		return s;
	}
	public static boolean palin(String s)
	{
		int i=0;
		int j=s.length()-1;
		while(i!=j)
		{
			if(s.charAt(i)!=s.charAt(j))return false;
			i++;
			j--;
		}
	   return true;	
	}
	

}


Compiler output:
a.cc:4:1: error: 'import' does not name a type
    4 | import java.io.BufferedReader;
      | ^~~~~~
a.cc:4:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:5:1: error: 'import' does not name a type
    5 | import java.io.IOException;
      | ^~~~~~
a.cc:5:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:6:1: error: 'import' does not name a type
    6 | import java.io.InputStreamReader;
      | ^~~~~~
a.cc:6:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:7:1: error: 'import' does not name a type
    7 | import java.io.PrintWriter;
      | ^~~~~~
a.cc:7:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:8:1: error: 'import' does not name a type
    8 | import java.util.Arrays;
      | ^~~~~~
a.cc:8:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:9:1: error: 'import' does not name a type
    9 | import java.util.StringTokenizer;
      | ^~~~~~
a.cc:9:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:11:1: error: expected unqualified-id before 'public'
   11 | public class Main {
      | ^~~~~~
Language: Java

import static java.lang.Math.abs;
import java.util.Scanner;

/**
 *
 * @author Owner
 */
public class Test20 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        Scanner sc=new Scanner(System.in);
        int a,b,x;
        
        x=sc.nextInt();
        a=sc.nextInt();
        b=sc.nextInt();
        
        if(abs(x-a)<abs(x-b)){
            System.out.println("A");
        }
        else{
            System.out.println("B");
        }
    }
    
}

Compiler output:
Main.java:8: error: class Test20 is public, should be declared in a file named Test20.java
public class Test20 {
       ^
1 error
Language: Java

public class Main{

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        Scanner sc=new Scanner(System.in);
        int a,b,x;
        
        x=sc.nextInt();
        a=sc.nextInt();
        b=sc.nextInt();
        
        if(abs(x-a)<abs(x-b)){
            System.out.println("A");
        }
        else{
            System.out.println("B");
        }
    }
    
}


Compiler output:
Main.java:8: error: cannot find symbol
        Scanner sc=new Scanner(System.in);
        ^
  symbol:   class Scanner
  location: class Main
Main.java:8: error: cannot find symbol
        Scanner sc=new Scanner(System.in);
                       ^
  symbol:   class Scanner
  location: class Main
Main.java:15: error: cannot find symbol
        if(abs(x-a)<abs(x-b)){
           ^
  symbol:   method abs(int)
  location: class Main
Main.java:15: error: cannot find symbol
        if(abs(x-a)<abs(x-b)){
                    ^
  symbol:   method abs(int)
  location: class Main
4 errors
Language: Java


import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

public class Main2 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		// 整数の入力
		int a = sc.nextInt();
		String v = String.valueOf(a);
		int length = v.length();
		String[] ar = new String[length];

		for (int i = 0; i < v.length(); i++) {
			String str = String.valueOf(v.charAt(i));
			ar[i] = str;
		}

		Arrays.sort(ar, Comparator.naturalOrder());
		System.out.println(ar[0]);

		sc.close();
	}

}


Compiler output:
Main.java:6: error: class Main2 is public, should be declared in a file named Main2.java
public class Main2 {
       ^
1 error
Language: Java

import java.util.Scanner;

public class Meal_Delivery {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int me = sc.nextInt();
		int a = sc.nextInt();
		int b = sc.nextInt();
		int farA = Math.abs(me - a);
		int farB = Math.abs(me - b);
		System.out.println(farA < farB ? "A" : "B");
	}
}


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

#include <iostream>
#include <math.h>
using namespace std;
int main ( ) {
	int x ;
	int a ;
	int b ;
	int A ;
	int B ;
	int n ;
	int f ;
	cin >> x >> a >> b ;
	f = printf ( x - a , fab ( x - a ) ) ;
	n = printf ( x - b , fab ( x - b ) ) ;
	if ( f < n ) {
		cout << A ;
	}
	else if ( n > f ) {
		cout << B ;
	}
	return 0 ; 
} 

Compiler output:
a.cc: In function 'int main()':
a.cc:13:30: error: 'fab' was not declared in this scope; did you mean 'fabs'?
   13 |         f = printf ( x - a , fab ( x - a ) ) ;
      |                              ^~~
      |                              fabs
Language: C++

#include<iostream>
#include<vector>
using namespace std;
int main(){
	vector<int> A;
	int x=0,y=0;
	bool xed=false;
	int buf;
	int n;
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>buf;
		A.push_back(buf);
	}
	std::sort(A.begin(),A.end(),std::greater<int>());
	for(int i=0;i<A.size();i++){
		if(A[i]==A[i+1]){
			if(!xed)
				x=A[i];
			else{
				y=A[i];
				break;
			}
			i++;
		}
	}
	cout<<x*y<<endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:14: error: 'sort' is not a member of 'std'; did you mean 'qsort'?
   15 |         std::sort(A.begin(),A.end(),std::greater<int>());
      |              ^~~~
      |              qsort
Language: C++

void qsort(int left, int right, int a[])
{
	if(left >= right)
		return;
	int l = left, r = right, m = (l + r) / 2;

	while(l <= r) {
		while(a[l] < a[m])
			++l;
		while(a[r] > a[m])
			--r;
		if(l <= r) {
			int tmp = a[l];
			a[l] = a[r];
			a[r] = tmp;
			++l;--r;
		}
	}
	qsort(left, r, a);
	qsort(l, right, a);
}


Compiler output:
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/14/../../../x86_64-linux-gnu/Scrt1.o: in function `_start':
(.text+0x17): undefined reference to `main'
collect2: error: ld returned 1 exit status
Language: C++

#include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
#include<cstdlib>
#define MAXN (int)1e5+10
using namespace std;

char s[MAXN];

int main()
{
	bool al[200];
	memset(al,false,sizeof(al));
	gets(s);
	for(int i=0;i<strlen(s);i++)
	{
		al[s[i]]=true;
	}
	for(char i='a';i<='z';i++)
	{
		if(!al[i])
		{
			cout<<char(i)<<endl;
			return 0;
		}
	}
	cout<<"None"<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:9: error: 'gets' was not declared in this scope; did you mean 'getw'?
   15 |         gets(s);
      |         ^~~~
      |         getw
Language: C++

#include<stdio.h>
int main() {
	int n, a, b,c,d;
	scanf_s("%d %d %d", &n,&a,&b);
	c = a - n; d = b - n;
	if (c <= 0) { c = -c; }
	if (d <= 0) { d = -d; }
	if (c<d) { printf("A"); }
	else { printf("B"); }

	return 0;

}

Compiler output:
a.cc: In function 'int main()':
a.cc:4:9: error: 'scanf_s' was not declared in this scope; did you mean 'scanf'?
    4 |         scanf_s("%d %d %d", &n,&a,&b);
      |         ^~~~~~~
      |         scanf
Language: C++

#include <iostream>
using namespace std;
int main()
{
    int x, a, b;
    cin >> x >> a >> b;
    int  s, x;
    s = x - a || a - x;
    t = x - b || b - x; 
    if(s - t > 0)
    {
        cout << "B" << endl;
    }
    if (s - t > 0)
    {
        cout << "A" <<endl;
    } 
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:13: error: redeclaration of 'int x'
    7 |     int  s, x;
      |             ^
a.cc:5:9: note: 'int x' previously declared here
    5 |     int x, a, b;
      |         ^
a.cc:9:5: error: 't' was not declared in this scope
    9 |     t = x - b || b - x;
      |     ^
Language: C++

#include <iostream>
using namespace std;
int main()
{
    int x, a, b;
    cin >> x >> a >> b;
    int x - a || a - x = s;
    int x - b || b - x = t;
    if(s - t > 0)
    {
        cout << "B" << endl;
    }
    if (s - t > 0)
    {
        cout << "A" <<endl;
    } 
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:11: error: expected initializer before '-' token
    7 |     int x - a || a - x = s;
      |           ^
a.cc:8:11: error: expected initializer before '-' token
    8 |     int x - b || b - x = t;
      |           ^
a.cc:9:8: error: 's' was not declared in this scope
    9 |     if(s - t > 0)
      |        ^
a.cc:9:12: error: 't' was not declared in this scope
    9 |     if(s - t > 0)
      |            ^
a.cc:13:9: error: 's' was not declared in this scope
   13 |     if (s - t > 0)
      |         ^
a.cc:13:13: error: 't' was not declared in this scope
   13 |     if (s - t > 0)
      |             ^
Language: C++

#include <cstdio>
#include <cstring>

char s[1000],ap[30]={"abcdefghijklmnopqrstuvwxyz"};
int ap2[30];
int main()
{
    gets(s);
    for(int i=0;i<strlen(s);i++)
    {
        for(int j=0;j<26;j++)
            if(s[i]==ap[j])
                ap2[j]=1;
    }
    for(int i=0;i<26;i++)
        if(ap2[i]==0)
        {
            printf("%c",ap[i]);
            return 0;
        }
    printf("None");
}


Compiler output:
a.cc: In function 'int main()':
a.cc:8:5: error: 'gets' was not declared in this scope; did you mean 'getw'?
    8 |     gets(s);
      |     ^~~~
      |     getw
Language: C++

#include <iostream>
using namespace std;

int main ( ) {
	int x ;
	int a ;
	int b ;
	cin >> x >> a >> b ;
	if ( ( x - a ) < ( x - b ) ) {
		cout << A ;
	}
	else if ( ( x - a ) > ( x - b ) ) {
		cout << B ;
	}
	else if ( ( x - a ) > ( b - x ) ) {
		cout << B ;
	}
	else if ( ( a - x ) > ( x - b ) ) {
		cout << B ;
	}
	else if ( ( x - a ) < ( b - x ) ) {
		cout << A ;
	}
	else if ( ( a - x ) < ( x - b ) ) {
		cout << A ;
	}
	return 0 ; 
} 

Compiler output:
a.cc: In function 'int main()':
a.cc:10:25: error: 'A' was not declared in this scope
   10 |                 cout << A ;
      |                         ^
a.cc:13:25: error: 'B' was not declared in this scope
   13 |                 cout << B ;
      |                         ^
a.cc:16:25: error: 'B' was not declared in this scope
   16 |                 cout << B ;
      |                         ^
a.cc:19:25: error: 'B' was not declared in this scope
   19 |                 cout << B ;
      |                         ^
a.cc:22:25: error: 'A' was not declared in this scope
   22 |                 cout << A ;
      |                         ^
a.cc:25:25: error: 'A' was not declared in this scope
   25 |                 cout << A ;
      |                         ^
Language: C++

#include<bits/stdc++.h>
using namespace std;
int n,a,b,aa,bb;
int main(){
	cin>>n>>a>>b;
	if(a-n>0){
		aa=a-n;
	}
	else{
		aa=0-a+n;
	}
	if(b-n>0){
		bb=b-n;
	}
	else{
		bb=0-b+n;
	}
	if(aa>bb){
		cout<<"A"<<endl;
	}
	else cout<<"B"<<endl;
	return 0
}

Compiler output:
a.cc: In function 'int main()':
a.cc:22:17: error: expected ';' before '}' token
   22 |         return 0
      |                 ^
      |                 ;
   23 | }
      | ~
Language: C++

using namespace std;

int main()
{
	int a, b, x;
	cin >> x >> a >> b;
	string ans = "";

	if (x - a < b - x) ans = "A";
	else ans = "B";

	cout << ans << endl;

    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:6:9: error: 'cin' was not declared in this scope
    6 |         cin >> x >> a >> b;
      |         ^~~
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:7:9: error: 'string' was not declared in this scope
    7 |         string ans = "";
      |         ^~~~~~
a.cc:1:1: note: 'std::string' is defined in header '<string>'; this is probably fixable by adding '#include <string>'
  +++ |+#include <string>
    1 | using namespace std;
a.cc:9:28: error: 'ans' was not declared in this scope
    9 |         if (x - a < b - x) ans = "A";
      |                            ^~~
a.cc:10:14: error: 'ans' was not declared in this scope
   10 |         else ans = "B";
      |              ^~~
a.cc:12:9: error: 'cout' was not declared in this scope
   12 |         cout << ans << endl;
      |         ^~~~
a.cc:12:9: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:12:17: error: 'ans' was not declared in this scope
   12 |         cout << ans << endl;
      |                 ^~~
a.cc:12:24: error: 'endl' was not declared in this scope
   12 |         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: C++

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
char s[100001];
bool a[27];
bool none;
char omg;
int main()
{
	gets(s);
	int str=strlen(s);
	for(int i=0;i<str;i++)
	{
		a[s[i]-'a']=1;
	}
	for(int i=0;i<26;i++){
		if(a[i]==0)
		{
			none=1;
			omg=i+'a';break;
		}
		
	}
	if(none==0)cout<<"None"<<endl;
	else cout<<omg<<endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:12:9: error: 'gets' was not declared in this scope; did you mean 'getw'?
   12 |         gets(s);
      |         ^~~~
      |         getw
Language: C++

#include<iostream>
#include <string>
#include <vector>
#include <set>
#include <queue>
#include <algorithm>
#include <map>
#include <stack>
#include <string.h>
#include <utility>
#include <functional>
#include <list>
#include<limits.h>
#include<stdio.h>
#include<windows.h>
#define rep(i,n) for (int i=0;i<n;i++)
#define IT iterator
#define Size(n) (int)((n).size()) 
#define pa pair
#define all(n) (n).begin(),(n).end
#define _abs(a) ((a)>0?(a):-(a))
#define inf 1<<32
using namespace std;
int x,a,b;
int main(){
	cin>>x>>a>>b;
	if(_abs(x-a)<_abs(x-b)) cout<<"A"<<endl;
	else cout<<"B"<<endl;
	return 0;
}

Compiler output:
a.cc:15:9: fatal error: windows.h: No such file or directory
   15 | #include<windows.h>
      |         ^~~~~~~~~~~
compilation terminated.
Language: C

#include<stdio.h>

int main()
{
 int x,a,b;
 scanf(" %d %d %d", &x,&,a, &b);
 if(abs(x-a) > abs(x-b))
  puts("B");
 else
  puts("A");
 return(0);
}

Compiler output:
main.c: In function 'main':
main.c:6:25: error: expected expression before ',' token
    6 |  scanf(" %d %d %d", &x,&,a, &b);
      |                         ^
main.c:7:5: error: implicit declaration of function 'abs' [-Wimplicit-function-declaration]
    7 |  if(abs(x-a) > abs(x-b))
      |     ^~~
main.c:2:1: note: include '<stdlib.h>' or provide a declaration of 'abs'
    1 | #include<stdio.h>
  +++ |+#include <stdlib.h>
    2 |
Language: C++

int main()
{
	int x, a, b;
	int wa = scanf("%d,%d,%d", &x, &a, &b);
	if(a - x < b - x)printf("A");
	else printf("B");
}

Compiler output:
a.cc: In function 'int main()':
a.cc:4:18: error: 'scanf' was not declared in this scope
    4 |         int wa = scanf("%d,%d,%d", &x, &a, &b);
      |                  ^~~~~
a.cc:5:26: error: 'printf' was not declared in this scope
    5 |         if(a - x < b - x)printf("A");
      |                          ^~~~~~
a.cc:1:1: note: 'printf' is defined in header '<cstdio>'; this is probably fixable by adding '#include <cstdio>'
  +++ |+#include <cstdio>
    1 | int main()
a.cc:6:14: error: 'printf' was not declared in this scope
    6 |         else printf("B");
      |              ^~~~~~
a.cc:6:14: note: 'printf' is defined in header '<cstdio>'; this is probably fixable by adding '#include <cstdio>'
Language: C++

int x,a,b; si(x);si(a);si(b);
if(abs(x-a)<abs(x-b)) puts("A");
else puts("B");



Compiler output:
a.cc:1:14: error: expected constructor, destructor, or type conversion before '(' token
    1 | int x,a,b; si(x);si(a);si(b);
      |              ^
a.cc:1:20: error: expected constructor, destructor, or type conversion before '(' token
    1 | int x,a,b; si(x);si(a);si(b);
      |                    ^
a.cc:1:26: error: expected constructor, destructor, or type conversion before '(' token
    1 | int x,a,b; si(x);si(a);si(b);
      |                          ^
a.cc:2:1: error: expected unqualified-id before 'if'
    2 | if(abs(x-a)<abs(x-b)) puts("A");
      | ^~
a.cc:3:1: error: expected unqualified-id before 'else'
    3 | else puts("B");
      | ^~~~
Language: C

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

int main(void){
  int x, a, b;
  scanf("%d %d %d", &x, &a, &b);
  A = a-x;
  B = b-x;
  
  if(A<0) A = -A;
  if(B<0) B = -B;
  
  if(A<B){
    print("A\n");
  }else{
    print("B\n");
  }
  
  return 0;
}

Compiler output:
main.c: In function 'main':
main.c:7:3: error: 'A' undeclared (first use in this function)
    7 |   A = a-x;
      |   ^
main.c:7:3: note: each undeclared identifier is reported only once for each function it appears in
main.c:8:3: error: 'B' undeclared (first use in this function)
    8 |   B = b-x;
      |   ^
main.c:14:5: error: implicit declaration of function 'print'; did you mean 'printf'? [-Wimplicit-function-declaration]
   14 |     print("A\n");
      |     ^~~~~
      |     printf
Language: C++

x, a, b = (int(i) for i in input().split())
if abs(x-a) > abs(x-b):
    print(A)
else:
    print(B)

Compiler output:
a.cc:1:1: error: 'x' does not name a type
    1 | x, a, b = (int(i) for i in input().split())
      | ^
Language: C++

#include <iostream>
#include <string>
#include <vector>
#include <cstdio>
#include <set>
#include <queue>
#include <algorithm>
#include <cstring> 
#include <map>
#include <cmath>
#include <cstdio>
#include <sstream>
#include <stack>
#include <ctime>
#include <string.h>
#include <utility>
#include <cstdlib>
#include <functional>
#include <deque>
#include <list>
#include<limits.h>
#include<stdio.h>
#include<windows.h>
#define open_in(n) freopen("n","r",stdin)
#define open_out(n) freopen("n","w",stdout)
#define rep(i,n) for (int i=0;i<n;i++)
#define repw(i,w) for(int i=w;i>0;i--)
#define repn(i,m,n) for (int i=n;i<m;i++)
#define for_all(it,n) for(__typeof((n).begin()) it=(n).begin();it!=(n).end();it++)
#define IT iterator
#define Size(n) (int)((n).size()) 
#define pb push_back
#define mpa make_pair
#define pa pair
#define all(n) (n).begin(),(n).end
#define dump(n) cerr<<#n<<"="<<(n)<<endl 
#define _abs(a) ((a)>0?(a):-(a))
#define inf 1<<32
using namespace std;
template <class t>
	t abs2(const t &x){
		return (x<0?-x:x);
	}
template <class t>	
	t max2(const t &x,const t &y){
		return (x>y?x:y);
	}
template <class t>
	t min2(const t &x,const t &y){
		return (x<y?x:y);
	}
template <class t>
    t gcd(const t &x,const t &y){
	    return x ? gcd(y%x,x) : y;
    }
typedef pair<int,int> pi;
typedef vector<int> vi;
typedef long long ll;
typedef map<int,int> mii;
typedef queue<int> qi;
typedef set<int> si;
int x,a,b;
int main(){
	cin>>x>>a>>b;
	if(_abs(x-a)<_abs(x-b)) cout<<"A"<<endl;
	else cout<<"B"<<endl;
	return 0;
}

Compiler output:
a.cc:23:9: fatal error: windows.h: No such file or directory
   23 | #include<windows.h>
      |         ^~~~~~~~~~~
compilation terminated.
Language: C++

#include <iostream>
void main(void){
    double x, a, b;
    cin >> x;
    cin >> a;
    cin >> b;
    double dist1 = x - a;
    if(dist1 < 0) dist1 *= -1;
    double dist2 = x - b;
    if(dist2 < 0) dist2 *= -1;
    if(dist1 > dist2) cout << 'A';
    else cout << 'B';
}

Compiler output:
a.cc:2:1: error: '::main' must return 'int'
    2 | void main(void){
      | ^~~~
a.cc: In function 'int main()':
a.cc:4:5: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    4 |     cin >> x;
      |     ^~~
      |     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:11:23: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   11 |     if(dist1 > dist2) cout << 'A';
      |                       ^~~~
      |                       std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:12:10: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   12 |     else cout << 'B';
      |          ^~~~
      |          std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
Language: C++

x, a, b = [int(i) for  i in input().split()]
if abs(x-a) < abs(x-b):
    print('A')
else:
    print('B')

Compiler output:
a.cc:1:1: error: 'x' does not name a type
    1 | x, a, b = [int(i) for  i in input().split()]
      | ^
Language: Java

import java.util.Scanner;

class Main {
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        int x = in.nextInt(), a = in.nextInt(), b= in.nextInt();
            if(Math.abs(a - x) > Math.abs(b - x)){
                System.out.println("A");
            }else{
                System.out.println("B");
            }
        }
    }
}

Compiler output:
Main.java:14: error: class, interface, enum, or record expected
}
^
1 error
Language: C++

#include <iostream>
using namespace std;

int x, a, b;
cin >> x >> a >> b;

if (abs(x-a) < abs(x-b)){
  cout << 'A' << endl;
}else{
  cout << 'B' << endl;
}

Compiler output:
a.cc:5:1: error: 'cin' does not name a type
    5 | cin >> x >> a >> b;
      | ^~~
a.cc:7:1: error: expected unqualified-id before 'if'
    7 | if (abs(x-a) < abs(x-b)){
      | ^~
a.cc:9:2: error: expected unqualified-id before 'else'
    9 | }else{
      |  ^~~~
Language: Java

import java.util.Scanner;

class Main {
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        int x = in.nextInt(), a = in.nextInt(), b= in.nextInt(){
            if(Math.abs(a - x) > Math.abs(b - x)){
                System.out.println("A");
            }else{
                System.out.println("B");
            }
        }
    }
}

Compiler output:
Main.java:6: error: ';' expected
        int x = in.nextInt(), a = in.nextInt(), b= in.nextInt(){
                                                               ^
1 error
Language: C

#include <stdio.h>
int main()
{
  char s[100001];
  char a[256] = {0};
  scanf("%s",&s);
  int i = 0;
  while (s[i])
  {
    a[s[i]]++;
    i++;
  }
  i = 0;
  while (i < 256)
  {
    if (i >= 'a' && i <= 'z' && a[i] == 0)
    {
      printf("%c",i);
      return (0);
    }
    i++;
  }
  if (f == 0)
    printf("None");
}

Compiler output:
main.c: In function 'main':
main.c:23:7: error: 'f' undeclared (first use in this function)
   23 |   if (f == 0)
      |       ^
main.c:23:7: note: each undeclared identifier is reported only once for each function it appears in
Language: C++

#include<bits/stdc++.h>
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); cout.precision(30);
using namespace std;

int main()
{
    IOS;
    string s;
    cin>>s;
    int t[25];
    int n = s.size();
    for(int i=0; i<n; i++){
        t[ord(s[i]-97)]++;
    }
    for(int i=0; i<25; i++){
        if(t[i]==0){
            cout<<char(i+97);
            return 0;
        }
    }
    cout<<"None";
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:13:11: error: 'ord' was not declared in this scope
   13 |         t[ord(s[i]-97)]++;
      |           ^~~
Language: C++

#include<bits/stdc++.h>
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); cout.precision(30);
using namespace std;

int main()
{
    IOS;
    string s;
    cin>>s;
    int t[25];
    int n = s.size();
    for(int i=0; i<n; i++){
        t[ord(s[i]-97]++;
    }
    for(int i=0; i<25; i++){
        if(t[i]==0){
            cout<<char(i+97);
            return 0;
        }
    }
    cout<<"None";
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:13:22: error: expected ')' before ']' token
   13 |         t[ord(s[i]-97]++;
      |              ~       ^
      |                      )
Language: C++

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

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
 
#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define rep1(i, n) for (ll i = 1; i <= (ll)(n); i++)
#define INF 10000000000
#define MOD 1000000007
using ll = long long;
using pint = pair<int,int>;
using pll = pair<ll,ll>;
using Graph = vector<vector<int>>;

int main(){
    set<char> m;
    string s; cin>>s;
    for(auto c:s)m.insert(c);
    for(char i = 'a'; i <= 'z'; i++){
        if(!m.count(i)){
            cout<<i<<endl;
            return 0;
        }
    }
    cout<<"None"<<endl;

Compiler output:
a.cc: In function 'int main()':
a.cc:26:24: error: expected '}' at end of input
   26 |     cout<<"None"<<endl;
      |                        ^
a.cc:16:11: note: to match this '{'
   16 | int main(){
      |           ^
Language: C++

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

int main(){
  string S;cin>>S;
  int l=S.size();
  vector<bool> A(26,false);
  for(int i=0;i<l;i++) A.at(S.at(i)-'a')=true;
  int l=-1;
  for(int j=0;j<26;j++){
    if(!A.at(j)){
      l=j;
      break;
    }
  }
  if(l==-1) cout<<"None"<<endl;
  else cout<<(char)('a'+l)<<endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:9:7: error: redeclaration of 'int l'
    9 |   int l=-1;
      |       ^
a.cc:6:7: note: 'int l' previously declared here
    6 |   int l=S.size();
      |       ^
Language: C++

#include<iostream>

using namespace std;

int main()
{
	
	string s;
	bool a = true ;
	cin >> s;
	for (int i = 97; i <= 122; i++)
	{
		a = true;
		for (int j = 0; j < s.length(); j++)
		{
			if (char(i) == s[j])
			{
				a = false;
				continue;
			
			}
		}
		if (a == true) {
			cout << char(i) ;
			return 0;
		}
	}
	if (a == false)
	{
		cout << "None" ;
		return 0;
	}


Compiler output:
a.cc: In function 'int main()':
a.cc:32:10: error: expected '}' at end of input
   32 |         }
      |          ^
a.cc:6:1: note: to match this '{'
    6 | {
      | ^
Language: C++

#include<iostream>

using namespace std;

int main()
{
	/*int n, x = 0, max = 0;
	cin >> n;
	char arr[n];*/

	string s;
	bool a = true ;
	cin >> s;
	for (int i = 97; i <= 122; i++)
	{
		a = true;
		for (int j = 0; j < s.length(); j++)
		{
			if (char(i) == s[j])
			{
				a = false;
				continue;
			
			}
		}
		if (a == true) {
			cout << char(i) << endl;
			return 0;
		}
	}
	if (a == false)
	{
		cout << "None" << endl;
		return 0;
	}

Compiler output:
a.cc: In function 'int main()':
a.cc:35:10: error: expected '}' at end of input
   35 |         }
      |          ^
a.cc:6:1: note: to match this '{'
    6 | {
      | ^
Language: C++

#include<iostream>

using namespace std;

int main()
{
	/*int n, x = 0, max = 0;
	cin >> n;
	char arr[n];*/

	string s;
	int a = 1;
	cin >> s;
	for (int i = 97; i <= 122; i++)
	{
		
		for (int j = 0; j < s.length(); j++)
		{
			if (char(i) == s[j])
			{
				a = 0;
				continue;
			}
		}
		if (a == 1) {
			cout << char(i) << endl;
			return 0;
		}
	}
	if (a == 0)
	{
		cout << "None" << endl;
		return 0;
	}

Compiler output:
a.cc: In function 'int main()':
a.cc:34:10: error: expected '}' at end of input
   34 |         }
      |          ^
a.cc:6:1: note: to match this '{'
    6 | {
      | ^
Language: C++

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


signed main()
{
  string s; cin >> s;
  map<char, int> mp;
  for (auto &&v : s)
  {
    mp[v]++;
  }
  char c = 'a';
  for (auto &&v : mp)
  {
    if (v.first == c)
    {
      c++;
    }
    else
    {
      cout << c << endl;
      return 0;
    }
    
  }
  if (c == 'z' + 1)
  {
    cout << "None" << endl;
  }
  else
  {
    cout << c << endl;
  }
  
  

Compiler output:
a.cc: In function 'int main()':
a.cc:35:4: error: expected '}' at end of input
   35 |   }
      |    ^
a.cc:7:1: note: to match this '{'
    7 | {
      | ^
Language: C++

#include <bits/stdc++.h>
using ll = long long;
using namespace std;
#define rep(i,n) for(int i=0, i##_len=(int)(n); i<i##_len; i++)
#define reps(i,n) for(int i=1 , i##_len=(int)(n);i<=i##_len;i++)
#define rrep(i,n) for(int i=((int)(n)-1);i>=0;i--)
#define rreps(i,n) for(int i=((int)(n));i>0;i--)
#define repi(i,x) for(auto i=(x).begin(),i##_fin=(x).end();i!=i##_fin;i++)
#define all(x) (x).begin(), (x).end()
#define F first
#define S second
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define eb emplace_back
string solve(bool a) { return ((a) ? "Yes" : "No"); }
typedef vector<int> Vi;
typedef vector<Vi> VVi;
typedef pair<int , int> Pi;
typedef vector<Pi> VPi;
typedef vector<long long> V;
typedef vector<V> VV;
typedef pair<long long , long long> P;
typedef vector<P> VP;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1;} return 0;}
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1;} return 0;}
template <class T, class U>ostream& operator<<(ostream& os, const pair<T, U>& p) {
	os << "(" << p.first << "," << p.second << ")";
	return os;
}
template <class T>ostream& operator<<(ostream& os, const vector<T>& v) {
	os << "{";
	rep(i, v.size()) {
		if (i) os << ",";
		os << v[i];
	}
	os << "}";
	return os;
}
template <class T, class U>istream& operator>>(istream& is, pair<T, U>& p) {
	is >> p.first >>p.second ;
	return is;
}
template <class T>istream& operator>>(istream& is,  vector<T>& v) {
	rep(i, v.size()) {
		is >> v[i];
	}
	return is;
}
const long long INFLL = 1LL<<60;
const int INF = 1<<30;
const double PI=acos(-1);
int main(){
	string s;
	int ans=0;
	cin >>s;
	set<char>dis;
	for(char i:s){
		dis.insert(i);
	}
	for (char i = 'a'; i <= 'z'; i++) {
		if(!dis.contains(i)){
			cout << i << endl;
			return 0;
		}
	}
	cout << "None" << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:62:25: error: 'class std::set<char>' has no member named 'contains'
   62 |                 if(!dis.contains(i)){
      |                         ^~~~~~~~
Language: C++

#include <bits/stdc++.h>
using ll = long long;
using namespace std;
#define rep(i,n) for(int i=0, i##_len=(int)(n); i<i##_len; i++)
#define reps(i,n) for(int i=1 , i##_len=(int)(n);i<=i##_len;i++)
#define rrep(i,n) for(int i=((int)(n)-1);i>=0;i--)
#define rreps(i,n) for(int i=((int)(n));i>0;i--)
#define repi(i,x) for(auto i=(x).begin(),i##_fin=(x).end();i!=i##_fin;i++)
#define all(x) (x).begin(), (x).end()
#define F first
#define S second
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define eb emplace_back
string solve(bool a) { return ((a) ? "Yes" : "No"); }
typedef vector<int> Vi;
typedef vector<Vi> VVi;
typedef pair<int , int> Pi;
typedef vector<Pi> VPi;
typedef vector<long long> V;
typedef vector<V> VV;
typedef pair<long long , long long> P;
typedef vector<P> VP;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1;} return 0;}
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1;} return 0;}
template <class T, class U>ostream& operator<<(ostream& os, const pair<T, U>& p) {
	os << "(" << p.first << "," << p.second << ")";
	return os;
}
template <class T>ostream& operator<<(ostream& os, const vector<T>& v) {
	os << "{";
	rep(i, v.size()) {
		if (i) os << ",";
		os << v[i];
	}
	os << "}";
	return os;
}
template <class T, class U>istream& operator>>(istream& is, pair<T, U>& p) {
	is >> p.first >>p.second ;
	return is;
}
template <class T>istream& operator>>(istream& is,  vector<T>& v) {
	rep(i, v.size()) {
		is >> v[i];
	}
	return is;
}
const long long INFLL = 1LL<<60;
const int INF = 1<<30;
const double PI=acos(-1);
int main(){
	string s;
	int ans=0;
	cin >>s;
	set<char>dis;
	for(char i:s){
		dis.insert(i);
	}
	for (char i = 'a';i<='z':i++){
		if(!dis.contains(i)){
			cout << ai << endl;
			return 0;
		}
	} cout << "None" << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:61:27: warning: range-based 'for' loops with initializer only available with '-std=c++20' or '-std=gnu++20' [-Wc++20-extensions]
   61 |         for (char i = 'a';i<='z':i++){
      |                           ^
a.cc:61:33: error: expected ';' before ':' token
   61 |         for (char i = 'a';i<='z':i++){
      |                                 ^
      |                                 ;
a.cc:67:1: error: expected primary-expression before '}' token
   67 | }
      | ^
a.cc:66:34: error: expected ')' before '}' token
   66 |         } cout << "None" << endl;
      |                                  ^
      |                                  )
   67 | }
      | ~                                 
a.cc:61:13: note: to match this '('
   61 |         for (char i = 'a';i<='z':i++){
      |             ^
a.cc:67:1: error: expected primary-expression before '}' token
   67 | }
      | ^
Language: C++

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

int main(){

string s;
  cin >> s;
bool app[26];
  for(int i=0;i<26;i++){
    app[i]=false;
  }
for(int i=0;s[i]!='\0';i++){
  app[s[i]-'a'] = true;
}
for(int i=0;i<n;i++){
if(!app[i]){
  printf("%c\n",(char)(i+'a'));
  return;
}
}
cout << "None" << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:15: error: 'n' was not declared in this scope
   15 | for(int i=0;i<n;i++){
      |               ^
a.cc:18:3: error: return-statement with no value, in function returning 'int' [-fpermissive]
   18 |   return;
      |   ^~~~~~
Language: C++

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


int main() {

	string S;
	cin >> S;

    bool b(26);
    for (int i = 0; i < 26; ++i) {
        b[i] = false;
    }

    for (int i = 0; i < S.size(); ++i) {
        b[S[i] - 'a'] == true;
    }

    for (int i = 0; i < 26; ++i) {
        if (!b[i]) {
            cout << (char)(i + 'a') << endl;
            return 0
        }
    }
    cout << "None" << endl;
    return 0;


}


Compiler output:
a.cc: In function 'int main()':
a.cc:15:10: error: invalid types 'bool[int]' for array subscript
   15 |         b[i] = false;
      |          ^
a.cc:19:10: error: invalid types 'bool[int]' for array subscript
   19 |         b[S[i] - 'a'] == true;
      |          ^
a.cc:23:15: error: invalid types 'bool[int]' for array subscript
   23 |         if (!b[i]) {
      |               ^
a.cc:25:21: error: expected ';' before '}' token
   25 |             return 0
      |                     ^
      |                     ;
   26 |         }
      |         ~
Language: C++

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


int main() {
	string s;
	cin>>s;
	for(int i=0;i<s.length();i++) g[s[i]-'a']++;
	for(int i=0;i<26;i++){
		if(g[i]==0){
			cout<<(char)(i+'a')<<endl;
			return 0;
		}
	}
	cout<<"None"<<endl;


}


Compiler output:
a.cc: In function 'int main()':
a.cc:11:39: error: 'g' was not declared in this scope
   11 |         for(int i=0;i<s.length();i++) g[s[i]-'a']++;
      |                                       ^
a.cc:13:20: error: 'g' was not declared in this scope
   13 |                 if(g[i]==0){
      |                    ^
Language: C++

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

int main(){
  string s; cin >> s;
  int check[26] = {};
  for(int i = 0; i < s.size(); i++){
    int t = s[i]-'a';
    check[t] = 1;
  }
  for(int i = 0; i < 26; i++){
    if(t[i] == 0) { 
      char ans = 'a' + i;
      cout << ans << endl;
      return 0;
    }
  }
  cout << "None" << endl;
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:14:8: error: 't' was not declared in this scope
   14 |     if(t[i] == 0) {
      |        ^
Language: C++

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

signed main(){
  string S;
  cin>>S;
  int A[26];
  rep(i,26)A[i]=0;
  rep(i,S.size())A[S[i]-'a']+=1;
  rep(i,26){
    if(A[i]==0){
      char ans='a'+i;
      cout<<ans<<endl;
      return 0;
    }
  }
  cout<<"None"<<endl;
  return 0;

Compiler output:
a.cc: In function 'int main()':
a.cc:21:12: error: expected '}' at end of input
   21 |   return 0;
      |            ^
a.cc:7:14: note: to match this '{'
    7 | signed main(){
      |              ^
Language: C++

#include <bits/stdc++.h>
#define f(i,j,k) for(int i=j;i<k;i++)
using namespace std;
int main(){
    string s;
    cin>>s;
    long long a[30]={}
    f(i,0,s.size()){
        a[s[i]-'a']++;
    }
    f(i,0,26) {
		if (alph[i] == 0) {
			cout << (char)(i + 'a') << endl;
			return 0;
		}
	}
	cout << "None" << endl;
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:2:18: error: expected ',' or ';' before 'for'
    2 | #define f(i,j,k) for(int i=j;i<k;i++)
      |                  ^~~
a.cc:8:5: note: in expansion of macro 'f'
    8 |     f(i,0,s.size()){
      |     ^
a.cc:8:7: error: 'i' was not declared in this scope
    8 |     f(i,0,s.size()){
      |       ^
a.cc:2:30: note: in definition of macro 'f'
    2 | #define f(i,j,k) for(int i=j;i<k;i++)
      |                              ^
a.cc:12:21: error: 'alph' was not declared in this scope
   12 |                 if (alph[i] == 0) {
      |                     ^~~~
Language: C++

#include <bits/stdc++.h>
#define f(i,j,k) for(int i=j;i<k;i++)
using namespace std;
int main(){
    string s;
    cin>>s;
    long long a[30]={}
    f(i,0,s.size()){
        a[s[i]-'a']++;
    }
    for (i,0,26) {
		if (alph[i] == 0) {
			cout << (char)(i + 'a') << endl;
			return 0;
		}
	}
	cout << "None" << endl;
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:2:18: error: expected ',' or ';' before 'for'
    2 | #define f(i,j,k) for(int i=j;i<k;i++)
      |                  ^~~
a.cc:8:5: note: in expansion of macro 'f'
    8 |     f(i,0,s.size()){
      |     ^
a.cc:8:7: error: 'i' was not declared in this scope
    8 |     f(i,0,s.size()){
      |       ^
a.cc:2:30: note: in definition of macro 'f'
    2 | #define f(i,j,k) for(int i=j;i<k;i++)
      |                              ^
a.cc:18:5: error: expected primary-expression before 'return'
   18 |     return 0;
      |     ^~~~~~
a.cc:17:32: error: expected ')' before 'return'
   17 |         cout << "None" << endl;
      |                                ^
      |                                )
   18 |     return 0;
      |     ~~~~~~                      
a.cc:11:9: note: to match this '('
   11 |     for (i,0,26) {
      |         ^
Language: C++

#include <bits/stdc++.h>
#define f(i,j,k) for(int i=j;i<k;i++)
using namespace std;
int main(){
    string s;
    cin>>s;
    long long a[30]={}
    f(i,0.s.size()){
        a[s[i]-'a']++;
    }
    for (i,0,26) {
		if (alph[i] == 0) {
			cout << (char)(i + 'a') << endl;
			return 0;
		}
	}
	cout << "None" << endl;
    return 0;
}


Compiler output:
a.cc:8:19: error: macro "f" requires 3 arguments, but only 2 given
    8 |     f(i,0.s.size()){
      |                   ^
a.cc:2:9: note: macro "f" defined here
    2 | #define f(i,j,k) for(int i=j;i<k;i++)
      |         ^
a.cc: In function 'int main()':
a.cc:8:5: error: expected ',' or ';' before 'f'
    8 |     f(i,0.s.size()){
      |     ^
a.cc:11:10: error: 'i' was not declared in this scope
   11 |     for (i,0,26) {
      |          ^
a.cc:18:5: error: expected primary-expression before 'return'
   18 |     return 0;
      |     ^~~~~~
a.cc:17:32: error: expected ')' before 'return'
   17 |         cout << "None" << endl;
      |                                ^
      |                                )
   18 |     return 0;
      |     ~~~~~~                      
a.cc:11:9: note: to match this '('
   11 |     for (i,0,26) {
      |         ^
Language: C++

#include <bits/stdc++.h>
using namespace std;
string t;
char ch;
char a[26]={'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u',
'v','w','x','y','z'};
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin>>t;
sort(t.begin(),t.end());
if(t.size()==1&&t[0]=='a') {
        cout << "None";
        return 0;
    }
set <char> s;
for(long long  i=0;i<t.size();i++){
    s.insert(t[i]);
}

for(long long i=0;i<s.size()=1;i++){
    if(s.count(a[i])==1)continue;
    else{
        cout<<a[i];
        return 0;
    }

}
cout<<"None";
return 0;}



Compiler output:
a.cc: In function 'int main()':
a.cc:21:20: error: lvalue required as left operand of assignment
   21 | for(long long i=0;i<s.size()=1;i++){
      |                   ~^~~~~~~~~
Language: C++

#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
#include <bitset>
#define M 1000000007
#define M1 998244353

#define tr(container, it) \
for(typeof(container.begin()) it = container.begin(); it != container.end(); it++)

#define fast                        \
  ios_base::sync_with_stdio(false); \
  cin.tie(NULL);

#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()

ll power(ll x, ll n)
{
    ll result = 1;
    while (n)
    {
        if (n % 2 == 1)
            result = result * x;
        n = n / 2;
        x = x * x;
    }
    return result;
}

ll gcd(ll a, ll b)
{
    if (!b)
        return a;
    return gcd(b, a % b);
}

ll lcm(ll a, ll b) {
    return (a * b) / gcd(a, b);
}

inline ll mul(ll x, ll y, ll m)
{
    ll z = 1LL * x * y;
    if (z >= m)
    {
        z %= m;
    }
    return z;
}

ll powmod(ll x, ll y, ll m)
{
    ll r = 1;
    while (y)
    {
        if (y & 1)
        {
            r = mul(r, x, m);
        }
        y >>= 1;
        x = mul(x, x, m);
    }
    return r;
}



void start()
{
    fast;
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif
}
/***********************************************************************************************************/



int main()
{
    start();
    int a, b, c, s;
    cin>>a>>b>>c>>s;
    int x=0, y=0, z=0;
    solve(a, b, c, s, x, y, z);
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:88:5: error: 'solve' was not declared in this scope
   88 |     solve(a, b, c, s, x, y, z);
      |     ^~~~~
Language: C++

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

int main() {
  string s;
  cin >> s;
  vector<bool> app(26);
  rep(i, 26) app[i] = false;
  rep(i, s.size()) app[s[i] - 'a'] = true;
  rep(i, 26) if(!app[i]) {
    string ans = i + 'a';
    cout << ans << endl;
    return 0;
  }
  
  cout << "None" << endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:14:20: error: conversion from 'int' to non-scalar type 'std::string' {aka 'std::__cxx11::basic_string<char>'} requested
   14 |     string ans = i + 'a';
      |                  ~~^~~~~
Language: C++

#include <iostream>
#include <vector>
#include <string>
#include <set>

using namespace std;

int main(){
  	string s;
  	stirng abc = "abcdefghijklmnopqrstuvwxyz";
  	cin >> s;
  	vector<int> num(26);
  	int N = s.size();
  	for(int i=0;i<N;i++){
      	int index = abc.find_first_of(s[i]);
      	num[index] = 1;
    }
  	int res = 0;
  	for(int i=0;i<N;i++){
      	if(num[i]==0) res++;
    }
  	cout << abc[res] << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:10:9: error: 'stirng' was not declared in this scope
   10 |         stirng abc = "abcdefghijklmnopqrstuvwxyz";
      |         ^~~~~~
a.cc:15:21: error: 'abc' was not declared in this scope; did you mean 'abs'?
   15 |         int index = abc.find_first_of(s[i]);
      |                     ^~~
      |                     abs
a.cc:22:17: error: 'abc' was not declared in this scope; did you mean 'abs'?
   22 |         cout << abc[res] << endl;
      |                 ^~~
      |                 abs
Language: C++

#include <bits/stdc++.h>
using namespace std;
#define SPEED ios::sync_with_stdio(false); cin.tie(0); cout.tie(0)
#define int long long
#define ld long double
#define fi first
#define se second
#define all(uiet) uiet.begin(),uiet.end()
#define read(UIET) for(int i = 0; i < n; ++i) cin >> UIET[i]
#define out(UIET) for(int i = 0; i < n; ++i) cout << UIET[i] << " "
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define vpp vector<pair< int, int > >
#define pll pair<int , int >
#define ppll pair < pll , pll >
#define debug(n1) cout << n1 << endl
#define len(a) ((int) (a).size())
#define endl "\n"
#define mod 1000000007
const int INF=(1LL<<60)-1;
bool isPerfectSquare(long double x) {   
    long double sr = sqrt(x); 
    return ((sr - floor(sr)) == 0); 
} 
bool isPrime(int x){
    for(int i = 2; i * i <= x; ++i){
        if(x % i == 0) return 0;
    }
    return 1;
}
int fun(int n){
    if(n & 1) return 3 * n + 1;
    else return n/2;
}
int32_t main(){
    SPEED;
    string s;
    cin >> s;
    set<char> su;
    if(len(s) == 1 && s[0] == 'a') {
        cout << "None";
        return 0;
    }
    for(char c: s){
        su.insert(c);
    }
    if(len(su) == 26){
        cout << "None" ;
        return 0;
    }
    for(char c = 'a'; c <= 'z'; ++i){
        if(!su.count(c)){
            cout << c ;
            return 0;
        }
    }
}

Compiler output:
a.cc: In function 'int32_t main()':
a.cc:52:35: error: 'i' was not declared in this scope
   52 |     for(char c = 'a'; c <= 'z'; ++i){
      |                                   ^
Language: C++

#include <bits/stdc++.h>
using namespace std;
 
 
int main() {
 
  string s;
  cin>>s;

  vector<int> found_char(26,0);
  for(int i=0;i<s.size();i++){
    char wk=s.at(i);
    found_char.at(wk-'a')++;
  }

  bool flg=false;
  char not_found='?';a
  for(int i=0;i<26;i++){
    if(found_char.at(i)==0){
      not_found=(char)(i+'a');
      break;
    }

    if(i==s.size()-1)
      flg=true;
  }


  if(flg)
    cout<<"None"<<endl;
  else
    cout<<not_found<<endl;

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:17:22: error: 'a' was not declared in this scope
   17 |   char not_found='?';a
      |                      ^
a.cc:18:15: error: 'i' was not declared in this scope
   18 |   for(int i=0;i<26;i++){
      |               ^
Language: Java

public class Main {
	
	static String letters;
	public static void main (String[] args)
	{
		Scanner sc = new Scanner(System.in);
		letters=sc.next();
		
		System.out.println (finder(letters));
	}
	
	
	
	static String finder (String str)
	{
		int count ;
		for(int i = 0; i<26;i++)
		{
			count = 0;
			for (int j = 0; j <letters.length() ;j++)
			{
				if (letters.charAt(j)==('a'+i))
					count++;
			}	
			if (count==0)
				return((char)('a'+i) +"");
		}
		return ("None");
	}
}

Compiler output:
Main.java:6: error: cannot find symbol
		Scanner sc = new Scanner(System.in);
		^
  symbol:   class Scanner
  location: class Main
Main.java:6: error: cannot find symbol
		Scanner sc = new Scanner(System.in);
		                 ^
  symbol:   class Scanner
  location: class Main
2 errors