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

#include<bits/stdc++.h>
using namespace std;using int32=int_fast32_t;using uint32=uint_fast32_t;using int64=int_fast64_t;using uint64=uint_fast64_t;using pi=pair<int32,int32>;using pll=pair<int64,int64>;using vi=vector<int32>;using vvi=vector<vector<int32>>;using vll=vector<int64>;using ll=int64;using ull=uint64;
#define all(x) x.begin(),x.end()
inline ll read(){ll x=0,f=1;char c=getchar();while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();}while(c>='0'&&c<='9')x=x*10+c-'0',c=getchar();return x*f;}
inline char read_c(){char c=getchar();while(c<'!'||c>'~'){c=getchar();}return c;}
void Main(){
    map<char char> m;
    m['T']='A';m['A']='T';m['G']='C';m['C']='G';
    char b = read_c();
    printf("%c\n", m[b]);
}
int main(){cin.tie(nullptr);ios::sync_with_stdio(false);Main();return 0;}

Compiler output:
a.cc: In function 'void Main()':
a.cc:7:9: error: two or more data types in declaration of 'type name'
    7 |     map<char char> m;
      |         ^~~~
a.cc:7:18: error: wrong number of template arguments (1, should be at least 2)
    7 |     map<char char> m;
      |                  ^
In file included from /usr/include/c++/14/map:63,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:152,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_map.h:102:11: note: provided for 'template<class _Key, class _Tp, class _Compare, class _Alloc> class std::map'
  102 |     class map
      |           ^~~
a.cc:8:6: error: invalid types 'int[char]' for array subscript
    8 |     m['T']='A';m['A']='T';m['G']='C';m['C']='G';
      |      ^
a.cc:8:17: error: invalid types 'int[char]' for array subscript
    8 |     m['T']='A';m['A']='T';m['G']='C';m['C']='G';
      |                 ^
a.cc:8:28: error: invalid types 'int[char]' for array subscript
    8 |     m['T']='A';m['A']='T';m['G']='C';m['C']='G';
      |                            ^
a.cc:8:39: error: invalid types 'int[char]' for array subscript
    8 |     m['T']='A';m['A']='T';m['G']='C';m['C']='G';
      |                                       ^
a.cc:10:21: error: invalid types 'int[char]' for array subscript
   10 |     printf("%c\n", m[b]);
      |                     ^
Language: C++

#include<bits/stdc++.h>
using namespace std;using int32=int_fast32_t;using uint32=uint_fast32_t;using int64=int_fast64_t;using uint64=uint_fast64_t;using pi=pair<int32,int32>;using pll=pair<int64,int64>;using vi=vector<int32>;using vvi=vector<vector<int32>>;using vll=vector<int64>;using ll=int64;using ull=uint64;
#define all(x) x.begin(),x.end()
inline ll read(){ll x=0,f=1;char c=getchar();while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();}while(c>='0'&&c<='9')x=x*10+c-'0',c=getchar();return x*f;}
inline char read_c(){char c=getchar();while(c<'!'||c>'~'){c=getchar();}return c;}
void Main(){
    map<char char> m = {{'A','T'},{'C','G'},{'T','A'},{'G','C'},};
    char b = read_c();
    printf("%c\n", m[b]);
}
int main(){cin.tie(nullptr);ios::sync_with_stdio(false);Main();return 0;}

Compiler output:
a.cc: In function 'void Main()':
a.cc:7:9: error: two or more data types in declaration of 'type name'
    7 |     map<char char> m = {{'A','T'},{'C','G'},{'T','A'},{'G','C'},};
      |         ^~~~
a.cc:7:18: error: wrong number of template arguments (1, should be at least 2)
    7 |     map<char char> m = {{'A','T'},{'C','G'},{'T','A'},{'G','C'},};
      |                  ^
In file included from /usr/include/c++/14/map:63,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:152,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_map.h:102:11: note: provided for 'template<class _Key, class _Tp, class _Compare, class _Alloc> class std::map'
  102 |     class map
      |           ^~~
a.cc:7:20: error: scalar object 'm' requires one element in initializer
    7 |     map<char char> m = {{'A','T'},{'C','G'},{'T','A'},{'G','C'},};
      |                    ^
Language: C++

#include<bits/stdc++.h>
using namespace std;using int32=int_fast32_t;using uint32=uint_fast32_t;using int64=int_fast64_t;using uint64=uint_fast64_t;using pi=pair<int32,int32>;using pll=pair<int64,int64>;using vi=vector<int32>;using vvi=vector<vector<int32>>;using vll=vector<int64>;using ll=int64;using ull=uint64;
#define all(x) x.begin(),x.end()
inline ll read(){ll x=0,f=1;char c=getchar();while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();}while(c>='0'&&c<='9')x=x*10+c-'0',c=getchar();return x*f;}
inline char read_c(){char c=getchar();while(c<'!'||c>'~'){c=getchar();}return c;}
void Main(){
    map<char char> m = {{'A','T'},{'C','G'},{'T','A'},{'G','C'}};
    char b = read_c();
    printf("%c\n", m[b]);
}
int main(){cin.tie(nullptr);ios::sync_with_stdio(false);Main();return 0;}

Compiler output:
a.cc: In function 'void Main()':
a.cc:7:9: error: two or more data types in declaration of 'type name'
    7 |     map<char char> m = {{'A','T'},{'C','G'},{'T','A'},{'G','C'}};
      |         ^~~~
a.cc:7:18: error: wrong number of template arguments (1, should be at least 2)
    7 |     map<char char> m = {{'A','T'},{'C','G'},{'T','A'},{'G','C'}};
      |                  ^
In file included from /usr/include/c++/14/map:63,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:152,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_map.h:102:11: note: provided for 'template<class _Key, class _Tp, class _Compare, class _Alloc> class std::map'
  102 |     class map
      |           ^~~
a.cc:7:20: error: scalar object 'm' requires one element in initializer
    7 |     map<char char> m = {{'A','T'},{'C','G'},{'T','A'},{'G','C'}};
      |                    ^
Language: Java

import java.util.*;

public class Main {
	public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		String b = sc.next();
		if (b == "A"){
			System.out.println("T");
		} else if (b == "T"){
			System.out.println("A");
		} else if (b == "C"){
			System.out.println("G");
		} else {
			System.out.println("C");
	}
}

Compiler output:
Main.java:16: error: reached end of file while parsing
}
 ^
1 error
Language: C++

#include <stdio.h>
int main(void){
  char b;
  scanf("%c",&c);
  if (c=='A') printf("T\n");
  else if (c=='T') printf("A\n");
  else if (c=='C') printf("G\n");
  else printf("C\n");
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:4:15: error: 'c' was not declared in this scope
    4 |   scanf("%c",&c);
      |               ^
Language: C++

b = input()
tmp = {'A':'T', 'T':'A', 'G':'C', 'C':'G'}
print(tmp[b])


Compiler output:
a.cc:1:1: error: 'b' does not name a type
    1 | b = input()
      | ^
a.cc:3:6: error: expected constructor, destructor, or type conversion before '(' token
    3 | print(tmp[b])
      |      ^
Language: C++

#include<stdio.h>
#include<string.h>

int main(){
  char s[10];
  int i, j, n, max=0
  
  
  if(scanf("%s", s)==0) return -1;
  n=strlen(s);
  
  for(i=0;i<n;i++){
    if(s[j]=='A'||s[j]=='C'||s[j]=='G'||s[j]=='T'){
      for(j=i;j<n;j++){
      	if(s[j]!='A'&&s[j]!='C'&&s[j]!='G'&&s[j]!='T') break;
      }
      if(max<(j-i)) max=j-i;
      i=j; 
    }
  }
  
  printf("%d", max);

  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:3: error: expected ',' or ';' before 'if'
    9 |   if(scanf("%s", s)==0) return -1;
      |   ^~
Language: C++

#include<stdio.h>

int main(){

  char c;
	
  if(scanf("%c", &c)==0) return -1;
  if(c==A)	putchar('T');
  else if(c==C)	putchar('G');
  else if(c==G) putchar('C');
  else putchar('A');
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:8:9: error: 'A' was not declared in this scope
    8 |   if(c==A)      putchar('T');
      |         ^
a.cc:9:14: error: 'C' was not declared in this scope
    9 |   else if(c==C) putchar('G');
      |              ^
a.cc:10:14: error: 'G' was not declared in this scope
   10 |   else if(c==G) putchar('C');
      |              ^
Language: C++

trans:: String -> Char
trans "A" = 'T'
trans "G" = 'C'
trans "T" = 'A'
trans "C" = 'G'

main:: IO()
main = do 
  str <- getLine
  putChar $ trans str

Compiler output:
a.cc:1:1: error: 'trans' does not name a type
    1 | trans:: String -> Char
      | ^~~~~
Language: C++

#include<iostream>
using namespace std;
int main(){
  char b;
  cin>>b;
  if(b=="A"){
   cout<<"T"¥n";
  }
  else if(b=="C"){
   cout<<"G"¥n";
  }
  else if(b=="T"){
   cout<<"A"¥n";
  }
  else if(b=="G"){
   cout<<"C"¥n";
  }
  return 0;
}


Compiler output:
a.cc:7:10: error: extended character ¥ is not valid in an identifier
    7 |    cout<<"T"¥n";
      |          ^
a.cc:7:15: warning: missing terminating " character
    7 |    cout<<"T"¥n";
      |               ^
a.cc:7:15: error: missing terminating " character
    7 |    cout<<"T"¥n";
      |               ^~
a.cc:10:10: error: extended character ¥ is not valid in an identifier
   10 |    cout<<"G"¥n";
      |          ^
a.cc:10:15: warning: missing terminating " character
   10 |    cout<<"G"¥n";
      |               ^
a.cc:10:15: error: missing terminating " character
   10 |    cout<<"G"¥n";
      |               ^~
a.cc:13:10: error: extended character ¥ is not valid in an identifier
   13 |    cout<<"A"¥n";
      |          ^
a.cc:13:15: warning: missing terminating " character
   13 |    cout<<"A"¥n";
      |               ^
a.cc:13:15: error: missing terminating " character
   13 |    cout<<"A"¥n";
      |               ^~
a.cc:16:10: error: extended character ¥ is not valid in an identifier
   16 |    cout<<"C"¥n";
      |          ^
a.cc:16:15: warning: missing terminating " character
   16 |    cout<<"C"¥n";
      |               ^
a.cc:16:15: error: missing terminating " character
   16 |    cout<<"C"¥n";
      |               ^~
a.cc: In function 'int main()':
a.cc:6:7: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    6 |   if(b=="A"){
      |      ~^~~~~
a.cc:7:10: error: unable to find string literal operator 'operator""\U000000a5n' with 'const char [2]', 'long unsigned int' arguments
    7 |    cout<<"T"¥n";
      |          ^~~~~
a.cc:9:12: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    9 |   else if(b=="C"){
      |           ~^~~~~
a.cc:10:10: error: unable to find string literal operator 'operator""\U000000a5n' with 'const char [2]', 'long unsigned int' arguments
   10 |    cout<<"G"¥n";
      |          ^~~~~
a.cc:12:12: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   12 |   else if(b=="T"){
      |           ~^~~~~
a.cc:13:10: error: unable to find string literal operator 'operator""\U000000a5n' with 'const char [2]', 'long unsigned int' arguments
   13 |    cout<<"A"¥n";
      |          ^~~~~
a.cc:15:12: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   15 |   else if(b=="G"){
      |           ~^~~~~
a.cc:16:10: error: unable to find string literal operator 'operator""\U000000a5n' with 'const char [2]', 'long unsigned int' arguments
   16 |    cout<<"C"¥n";
      |          ^~~~~
Language: Java

package com.hrsnkawagoe.p1;

import java.util.Scanner;

public class test1 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		String input;
		Scanner sc=new Scanner(System.in);
		input=sc.next();
		String output=null;
		if(input.equals("A")) {
			output="T";
		}else if(input.equals("C")) {
			output="G";
		}else if(input.equals("G")) {
			output="C";
		}else if(input.equals("T")) {
			output="A";
		}
		System.out.println(output);
	}

}


Compiler output:
Main.java:5: error: class test1 is public, should be declared in a file named test1.java
public class test1 {
       ^
1 error
Language: C++

#include <cmath>
#include <cstdio>
#include <map>
#include <iostream>
using namespace std;

char a;
cin >> a;
map<char, char> b;
b.insert(make_pair("A", "T"));
b.insert(make_pair("T", "A"));
b.isnert(make_pair("G", "C"));
b.insert(make_pair("C", "G"));
cout << b[a] << endl;

Compiler output:
a.cc:8:1: error: 'cin' does not name a type
    8 | cin >> a;
      | ^~~
a.cc:10:1: error: 'b' does not name a type
   10 | b.insert(make_pair("A", "T"));
      | ^
a.cc:11:1: error: 'b' does not name a type
   11 | b.insert(make_pair("T", "A"));
      | ^
a.cc:12:1: error: 'b' does not name a type
   12 | b.isnert(make_pair("G", "C"));
      | ^
a.cc:13:1: error: 'b' does not name a type
   13 | b.insert(make_pair("C", "G"));
      | ^
a.cc:14:1: error: 'cout' does not name a type
   14 | cout << b[a] << endl;
      | ^~~~
Language: C++

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

int main() {
  string b;
  cin>>b;
  if (b==A) {
    cout<<"T"<<endl;
  }
  else if (b==T) {
    cout<<"A"<<endl;
  }
  else if (b==G) {
    cout<<"C"<<endl;
  }
  else {
    cout<<"G"<<endl;
  }
  
}


Compiler output:
a.cc: In function 'int main()':
a.cc:7:10: error: 'A' was not declared in this scope
    7 |   if (b==A) {
      |          ^
a.cc:10:15: error: 'T' was not declared in this scope
   10 |   else if (b==T) {
      |               ^
a.cc:13:15: error: 'G' was not declared in this scope
   13 |   else if (b==G) {
      |               ^
Language: C++

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

int main() {
  char a;
  cin >> a;
  if (a == 'A') cout << T << endl;
  else if (a == 'C') cout << G << endl;
  else if (a == 'G') cout << C << endl;
  else cout << A << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:25: error: 'T' was not declared in this scope
    7 |   if (a == 'A') cout << T << endl;
      |                         ^
a.cc:8:30: error: 'G' was not declared in this scope
    8 |   else if (a == 'C') cout << G << endl;
      |                              ^
a.cc:9:30: error: 'C' was not declared in this scope
    9 |   else if (a == 'G') cout << C << endl;
      |                              ^
a.cc:10:16: error: 'A' was not declared in this scope
   10 |   else cout << A << endl;
      |                ^
Language: C++

#include<stdio.h>

int main()
{

	char b, c;

	scanf_s("%c", &b);

	if (b == 'A')c = 'T';
	if (b == 'T')c = 'A';
	if (b == 'C')c = 'G';
	if (b == 'G')c = 'C';







	printf("%c", c);


	return(0);
}


Compiler output:
a.cc: In function 'int main()':
a.cc:8:9: error: 'scanf_s' was not declared in this scope; did you mean 'scanf'?
    8 |         scanf_s("%c", &b);
      |         ^~~~~~~
      |         scanf
Language: C++

#include "pch.h"
#include<stdio.h>

int main()
{

	char b, c;

	scanf_s("%c", &b);

	if (b == 'A')c = 'T';
	if (b == 'T')c = 'A';
	if (b == 'C')c = 'G';
	if (b == 'G')c = 'C';







	printf("%c", c);


	return(0);
}


Compiler output:
a.cc:1:10: fatal error: pch.h: No such file or directory
    1 | #include "pch.h"
      |          ^~~~~~~
compilation terminated.
Language: C++

#include<bits/stdc++.h>
using name space std;
char c;
int main()
{
 while(cin>>c)
 {
   if(c=='A') cout<<"T\n";
   if(c=='C') cout<<"G\n"; 
   if(c=='T') cout<<"A\n"; 
   if(c=='G') cout<<"C\n"; 
 }
  
}

Compiler output:
a.cc:2:7: error: expected nested-name-specifier before 'name'
    2 | using name space std;
      |       ^~~~
a.cc: In function 'int main()':
a.cc:6:8: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |  while(cin>>c)
      |        ^~~
      |        std::cin
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:146,
                 from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:8:15: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    8 |    if(c=='A') cout<<"T\n";
      |               ^~~~
      |               std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:9:15: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    9 |    if(c=='C') cout<<"G\n";
      |               ^~~~
      |               std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:10:15: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   10 |    if(c=='T') cout<<"A\n";
      |               ^~~~
      |               std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:11:15: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   11 |    if(c=='G') cout<<"C\n";
      |               ^~~~
      |               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<iostream>
#include<string>

int main(){
  std::string base;
  std::cin >> base;
  switch(base){
    case "A":
      std::cout<<"T";
    case "T":
      std::cout<<"A";
    case "G":
      std::cout<<"C";
    case "C":
      std::cout<<"G";
  }
  std::cout << std::endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:10: error: switch quantity not an integer
    7 |   switch(base){
      |          ^~~~
Language: C

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

static int max( int a, int b );
static int issATCG( int ca );
static int cntATCGstr( char *str );

void main()
{
    char str[10+1];
    int  len;
    int  strlen_max;
    scanf( "%s", str );
    len = strlen( str );
    strlen_max = 0;
    for( int i = 0; i < len; i++ ){
        if( !issATCG( str[ i ] ) ) continue;
        strlen_max = max( strlen_max, cntATCGstr( &str[ i ] ) );
    }
    printf("%d\n", strlen_max );
    exit(0);
}
static int max( int a, int b )
{
    return (a >= b)?a:b;
}
static int issATCG( int ch )
{
    if( ca == 'A' || ca == 'T'|| ca == 'C' || ca == 'G' ){
        return 1;
    }
    return 0;
}
static int cntATCGstr( char *str )
{
    int i;
    for( i = 0; issATCGATCG( str[ i ] ); i++ );
    return i;
}

Compiler output:
main.c: In function 'issATCG':
main.c:30:9: error: 'ca' undeclared (first use in this function); did you mean 'ch'?
   30 |     if( ca == 'A' || ca == 'T'|| ca == 'C' || ca == 'G' ){
      |         ^~
      |         ch
main.c:30:9: note: each undeclared identifier is reported only once for each function it appears in
main.c: In function 'cntATCGstr':
main.c:38:17: error: implicit declaration of function 'issATCGATCG'; did you mean 'issATCG'? [-Wimplicit-function-declaration]
   38 |     for( i = 0; issATCGATCG( str[ i ] ); i++ );
      |                 ^~~~~~~~~~~
      |                 issATCG
Language: Java

import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int b= sc.nextInt();
		if(b == "A") {
			System.out.println("T");	
		}
		
	}
}

Compiler output:
Main.java:6: error: bad operand types for binary operator '=='
		if(b == "A") {
		     ^
  first type:  int
  second type: String
1 error
Language: C++

#include <bits/stdc++.h>


using namespace std;

#define endl '\n'
#define PB push_back
#define MP make_pair
#define LL long long
#define FOR(i,a,b) for(int i = (a); i <= (b); i++)
#define RE(i,n) FOR(i,1,n)
#define REP(i,n) FOR(i,0,(int)(n)-1)
#define R(i,n) REP(i,n)
#define VI vector<int>
#define PII pair<int,int>
#define LD long double
#define FI first
#define SE second
#define st FI
#define nd SE
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) ((int)(x).size())

typedef long long ll;

bool file=0,rt=1;
clock_t tStart ;
void FAST_IO();
////////////////////////

int main() {

    FAST_IO();
    cout << setprecision(5);
    cout << fixed;

    char c;
    cin >> c;

    if(c == 'A') {

        cout << 'T' << endl;
    }A
    else if(c == 'T') {

        cout << 'A' << endl;
    }
    else if(c == 'C') {
A
        cout << 'G' << endl;
    }
    else if(c == 'G') {

        cout << 'c' << endl;
    }


    return 0;
}

void FAST_IO()
{
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    //cout.tie(NULL);
    //cout.setf(ios::fixed);
    //cout.precision(2);
    if(rt && file){ tStart = clock(); }
    if(file){
    #ifndef _offline
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif
    }
}



Compiler output:
a.cc: In function 'int main()':
a.cc:43:6: error: 'A' was not declared in this scope
   43 |     }A
      |      ^
a.cc:48:5: error: 'else' without a previous 'if'
   48 |     else if(c == 'C') {
      |     ^~~~
a.cc:49:2: error: expected ';' before 'cout'
   49 | A
      |  ^
      |  ;
   50 |         cout << 'G' << endl;
      |         ~~~~
Language: C++

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

int main() {
  char c; cin >> c;
  string res;
  if (c == 'A') res = "T";
  else if (c == 'T') res = "A";
  else if (c == 'G') res = "C";
  else res = "G";
    cout << res << endl;
}

Compiler output:
a.cc:1:10: fatal error: iosream: No such file or directory
    1 | #include <iosream>
      |          ^~~~~~~~~
compilation terminated.
Language: Java

import java.util.*;
public class Main{
	public static void main(String[] args){
      Scanner sc = new Scanner(system.in);
      String a = sc.next();
      if(a.equals("A")){
        a = "T";
      }else if(a.equals("T")){
        a = "A";
      }else if(a.equals("G")){
        a = "C";
      }else{
        a = "G";
      }
      System.out.println(a);
    }
}

Compiler output:
Main.java:4: error: cannot find symbol
      Scanner sc = new Scanner(system.in);
                               ^
  symbol:   variable system
  location: class Main
1 error
Language: C++

#include <io.stream>

main(){
  string s;
  cin >> s;
  if(s=="T"){
    cout << "A";
  }
  else if(s=="A"){
   cout << "T";
  }
  else if(s=="C"){
    cout << "G";
  }
  else if(s=="G"){
    cout << "C";
  }
  else{
    cout << "Error";
  }
}


Compiler output:
a.cc:1:10: fatal error: io.stream: No such file or directory
    1 | #include <io.stream>
      |          ^~~~~~~~~~~
compilation terminated.
Language: C++

#include<io.stream>

main(){
  string s;
  cin >> s;
  if(s=="T"){
    cout << "A";
  }
  else if(s=="A"){
   cout << "T";
  }
  else if(s=="C"){
    cout << "G";
  }
  else if(s=="G"){
    cout << "C";
  }
  else{
    cout << "Error";
  }
}


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

#include<io.stream>

main(){
  string s;
  cin >> s;
  if(s=="T"){
    cout << "A";
  }
  else if(s=="A"){
   cout << "T";
  }
  else if(s=="C"){
    cout << "G";
  }
  else if(s=="G"){
    cout << "C";
  }
  else{
    cout << "Error";
  }
}

    
    AT CG

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

import java.util.*;

class Program
{
  static void Main(string[] args)
  {
    // get a char
    char a = str.charAt(args[0]);
    char val = 'C';
    if (a == 'A')
      val = 'T';
    else if (a == 'T')
      val = 'A';
    else if (a == 'C')
      val = 'G';
    else
      val = 'C';
    //output
		System.out.println(val);
  }
}

Compiler output:
Main.java:5: error: cannot find symbol
  static void Main(string[] args)
                   ^
  symbol:   class string
  location: class Program
Main.java:8: error: cannot find symbol
    char a = str.charAt(args[0]);
             ^
  symbol:   variable str
  location: class Program
2 errors
Language: Java

import static java.lang.System.*;
import java.util.*;

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

		char b = sc.next().toCharArray()[0];

		if (b == 'A')
			out.println('T');
		if (b == 'T')
			out.println('A');
		if (b == 'C')
			out.println('G');
		if (b == 'G')
			out.println('C');
	}
}


Compiler output:
Main.java:4: error: class Double_Helix is public, should be declared in a file named Double_Helix.java
public class Double_Helix {
       ^
1 error
Language: Java

import static java.lang.System.*;
import java.util.*;

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

        char b = sc.next().toCharArray()[0];

		if(b=='A') out.println('T');
		if(b=='T') out.println('A');
		if(b=='C') out.println('G');
		if(b=='G') out.println('C');
    }
}


Compiler output:
Main.java:4: error: class main is public, should be declared in a file named main.java
public class main {
       ^
1 error
Language: Java

public static void main(String[] args) {
		int b;
		int A = 1;
		int C = 2;
		int G = 3;
		int T = 4;
		
		b = A;
		
		if(b == 1) {
			System.out.println("T");
		}
		if(b == 2) {
			System.out.println("G");
		}
		if(b == 3) {
			System.out.println("C");
		}
		if(b == 4) {
			System.out.println("A");
		}

}


Compiler output:
Main.java:1: error: unnamed classes are a preview feature and are disabled by default.
public static void main(String[] args) {
              ^
  (use --enable-preview to enable unnamed classes)
1 error
Language: C++

#include<iosetream>

using namespace std;
int main(){
 char A;
  cin >> A;
  if (A=='A')
    cout <<'A'<<endl;
  else if (A=='C')
    cout <<'T'<<endl;
  else if (A=='G')
    cout <<'C'<<endl;
  else if (A=='T')
    cout <<'G'<<endl;
}

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

#include <stdio.h>
int main(){
  char b=0
  scanf("%s",&a);
 if(b=='A'){
   printf("T");
 }
  if(b=='T'){
    printf("A");
  }

 if(b=='C'){
   printf("G");
 }
  if(b=='G'){
    printf("C");
  }
  
  return 0;
}

  

Compiler output:
main.c: In function 'main':
main.c:4:3: error: expected ',' or ';' before 'scanf'
    4 |   scanf("%s",&a);
      |   ^~~~~
Language: C++

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

int mian() {
  char b;
  cin >> b;
  if(b == 'A') {
    cout << 'T' << endl;
  }else if(b == 'C') {
    cout << 'G' << endl;
  }else if(b == 'G') {
    cout << 'C' << endl;
  }else {
    cout << 'A' << endl;
  }
}

Compiler output:
a.cc: In function 'int mian()':
a.cc:16:1: warning: no return statement in function returning non-void [-Wreturn-type]
   16 | }
      | ^
/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: Java

import java.util.*;
public class Main{
	public static void main(String[] args){
    	Scanner scan = new Scanner(System.in);
      	char x = scan.nextLine();
      	switch(x){
          case 'A':
            System.out.println('T');
            break;
          case 'T':
            System.out.println('A');
            break;
          case 'C':
            System.out.println('G');
            break;
          case 'G':
            System.out.println('C');
            break;
        }
    }
}

Compiler output:
Main.java:5: error: incompatible types: String cannot be converted to char
      	char x = scan.nextLine();
      	                      ^
1 error
Language: C++

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

int main() {
  //AT GC
  string b;
  cin >> b;
  
  if (b==A) cout << "T" << endl;
  else if (b==T) cout << "A" << endl;
  else if (b==C) cout << "G" << endl;
  else cout << "C" << endl;
}
  
      
      


Compiler output:
a.cc: In function 'int main()':
a.cc:9:10: error: 'A' was not declared in this scope
    9 |   if (b==A) cout << "T" << endl;
      |          ^
a.cc:10:15: error: 'T' was not declared in this scope
   10 |   else if (b==T) cout << "A" << endl;
      |               ^
a.cc:11:15: error: 'C' was not declared in this scope
   11 |   else if (b==C) cout << "G" << endl;
      |               ^
Language: C++

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

int main() {
  //AT GC
  string b;
  cin >> b;
  
  if (b=A) cout << T << endl;
  else if (b=T) cout << A << endl;
  else if (b=C) cout << G << endl;
  else cout << G << endl;
}
  
      
      


Compiler output:
a.cc: In function 'int main()':
a.cc:9:9: error: 'A' was not declared in this scope
    9 |   if (b=A) cout << T << endl;
      |         ^
a.cc:9:20: error: 'T' was not declared in this scope
    9 |   if (b=A) cout << T << endl;
      |                    ^
a.cc:10:14: error: 'T' was not declared in this scope
   10 |   else if (b=T) cout << A << endl;
      |              ^
a.cc:11:14: error: 'C' was not declared in this scope
   11 |   else if (b=C) cout << G << endl;
      |              ^
a.cc:11:25: error: 'G' was not declared in this scope
   11 |   else if (b=C) cout << G << endl;
      |                         ^
a.cc:12:16: error: 'G' was not declared in this scope
   12 |   else cout << G << endl;
      |                ^
Language: C++

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

int main() {
  //AT GC
  string b;
  cin >> b;
  
  if (b=A) cout << T << endl;
  else if (b=T) cout << A << endl;
  else if (b=C) cout << G << endl;
  else cout << G << endl;
}
  
      
      


Compiler output:
a.cc:1:10: fatal error: bit/stdc++.h: No such file or directory
    1 | #include <bit/stdc++.h>
      |          ^~~~~~~~~~~~~~
compilation terminated.
Language: C++

main int(){
  char N;
  cin >> N;
  if(N == 'A'){
    cout << 'T' << endl;
  }else if(N == 'T'){
    cout << 'A' << endl;
  }else if(N == 'C'){
    cout << 'G' << endl;
  }else{
    cout << 'C' << endl;
  }
}

Compiler output:
a.cc:1:1: error: 'main' does not name a type
    1 | main int(){
      | ^~~~
Language: C++

#include <iostream>
using namespace std;
  
int main() {
  string b;
  string a;
 b = "A";
  
  if(b == "A" || b == "T"){
    if(b == "A"){a = "T";
                }
    if(b == "T"){a = "A";
                }
  };
  else(b == "C" || b == "G") {
    if(b == "C"){a = "G";
                }
    if(b == "G"){a = "C";
                };
  }

  
  cout << a << endl;
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:3: error: 'else' without a previous 'if'
   15 |   else(b == "C" || b == "G") {
      |   ^~~~
a.cc:15:29: error: expected ';' before '{' token
   15 |   else(b == "C" || b == "G") {
      |                             ^~
      |                             ;
Language: C++

#include <iostream>
using namespace std;
  
int main() {
  string b;
  string a;
 b = "A";
  
  if(b == "A" || b == "T"){
    if(b == "A"){a = "T";
                }
    if(b == "T"){a = "A";
                }
  };
  elseif(b == "C" || b == "G"){
    if(b == "C"){a = "G";
                }
    if(b == "G"){a = "C";
                };
  }

  
  cout << a << endl;
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:3: error: 'elseif' was not declared in this scope
   15 |   elseif(b == "C" || b == "G"){
      |   ^~~~~~
Language: C++

#include <iostream>
using namespace std;
  
int main() {
  char b;
  char a;
  cin >> b;
  
  if(b == "A" || b == "T"){
    if(b == "A"){a = "T";
                }
    if(b == "T"){a = "A";
                }
  };
  elseif(b == "C" || b == "G"){
    if(b == "C"){a = "G";
                }
    if(b == "G"){a = "C";
                };
  }

  
  cout << a << endl;
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:8: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    9 |   if(b == "A" || b == "T"){
      |      ~~^~~~~~
a.cc:9:20: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    9 |   if(b == "A" || b == "T"){
      |                  ~~^~~~~~
a.cc:10:10: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   10 |     if(b == "A"){a = "T";
      |        ~~^~~~~~
a.cc:10:22: error: invalid conversion from 'const char*' to 'char' [-fpermissive]
   10 |     if(b == "A"){a = "T";
      |                      ^~~
      |                      |
      |                      const char*
a.cc:12:10: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   12 |     if(b == "T"){a = "A";
      |        ~~^~~~~~
a.cc:12:22: error: invalid conversion from 'const char*' to 'char' [-fpermissive]
   12 |     if(b == "T"){a = "A";
      |                      ^~~
      |                      |
      |                      const char*
a.cc:15:12: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   15 |   elseif(b == "C" || b == "G"){
      |          ~~^~~~~~
a.cc:15:24: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   15 |   elseif(b == "C" || b == "G"){
      |                      ~~^~~~~~
a.cc:15:3: error: 'elseif' was not declared in this scope
   15 |   elseif(b == "C" || b == "G"){
      |   ^~~~~~
Language: C++

#include <iostream>
using namespace std;
  
int main() {
  char b;
  char a;
  cin >> b;
  
  if(b == "A" || b == "T"){
    if(b == "A"){a = "T"}
    if(b == "T"){a = "A"}}
  elseif(b == "C" || b == "G"){
    if(b == "C"){a = "G"}
    if(b == "G"){a = "C"}}

  
  cout << a << endl;
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:8: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    9 |   if(b == "A" || b == "T"){
      |      ~~^~~~~~
a.cc:9:20: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    9 |   if(b == "A" || b == "T"){
      |                  ~~^~~~~~
a.cc:10:10: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   10 |     if(b == "A"){a = "T"}
      |        ~~^~~~~~
a.cc:10:22: error: invalid conversion from 'const char*' to 'char' [-fpermissive]
   10 |     if(b == "A"){a = "T"}
      |                      ^~~
      |                      |
      |                      const char*
a.cc:10:25: error: expected ';' before '}' token
   10 |     if(b == "A"){a = "T"}
      |                         ^
      |                         ;
a.cc:11:10: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   11 |     if(b == "T"){a = "A"}}
      |        ~~^~~~~~
a.cc:11:22: error: invalid conversion from 'const char*' to 'char' [-fpermissive]
   11 |     if(b == "T"){a = "A"}}
      |                      ^~~
      |                      |
      |                      const char*
a.cc:11:25: error: expected ';' before '}' token
   11 |     if(b == "T"){a = "A"}}
      |                         ^
      |                         ;
a.cc:12:12: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   12 |   elseif(b == "C" || b == "G"){
      |          ~~^~~~~~
a.cc:12:24: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   12 |   elseif(b == "C" || b == "G"){
      |                      ~~^~~~~~
a.cc:12:3: error: 'elseif' was not declared in this scope
   12 |   elseif(b == "C" || b == "G"){
      |   ^~~~~~
Language: C++

#include <iostream>

  
int main() {
  char b;
  char a;
  cin >> b;
  
  if(b == "A" || b == "T"){
    if(b == "A"){a = "T"}
    if(b == "T"){a = "A"}}
  elseif(b == "C" || b == "G"){
    if(b == "C"){a = "G"}
    if(b == "G"){a = "C"}}

  
  cout << a << endl;
  
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    7 |   cin >> b;
      |   ^~~
      |   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:9:8: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    9 |   if(b == "A" || b == "T"){
      |      ~~^~~~~~
a.cc:9:20: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    9 |   if(b == "A" || b == "T"){
      |                  ~~^~~~~~
a.cc:10:10: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   10 |     if(b == "A"){a = "T"}
      |        ~~^~~~~~
a.cc:10:22: error: invalid conversion from 'const char*' to 'char' [-fpermissive]
   10 |     if(b == "A"){a = "T"}
      |                      ^~~
      |                      |
      |                      const char*
a.cc:10:25: error: expected ';' before '}' token
   10 |     if(b == "A"){a = "T"}
      |                         ^
      |                         ;
a.cc:11:10: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   11 |     if(b == "T"){a = "A"}}
      |        ~~^~~~~~
a.cc:11:22: error: invalid conversion from 'const char*' to 'char' [-fpermissive]
   11 |     if(b == "T"){a = "A"}}
      |                      ^~~
      |                      |
      |                      const char*
a.cc:11:25: error: expected ';' before '}' token
   11 |     if(b == "T"){a = "A"}}
      |                         ^
      |                         ;
a.cc:12:12: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   12 |   elseif(b == "C" || b == "G"){
      |          ~~^~~~~~
a.cc:12:24: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   12 |   elseif(b == "C" || b == "G"){
      |                      ~~^~~~~~
a.cc:12:3: error: 'elseif' was not declared in this scope
   12 |   elseif(b == "C" || b == "G"){
      |   ^~~~~~
a.cc:17:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   17 |   cout << a << 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:17:16: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   17 |   cout << a << 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 <iostream>
using namespace std
  
int main() {
  char b;
  char a;
  cin >> b;
  
  if(b == "A" || b == "T"){
    if(b == "A"){a = "T"}
    if(b == "T"){a = "A"}}
  elseif(b == "C" || b == "G"){
    if(b == "C"){a = "G"}
    if(b == "G"){a = "C"}}
  else {};
  
  cout << a << endl;
  
  return 0;
}

Compiler output:
a.cc:2:20: error: expected ';' before 'int'
    2 | using namespace std
      |                    ^
      |                    ;
    3 | 
    4 | int main() {
      | ~~~                 
a.cc: In function 'int main()':
a.cc:9:8: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    9 |   if(b == "A" || b == "T"){
      |      ~~^~~~~~
a.cc:9:20: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    9 |   if(b == "A" || b == "T"){
      |                  ~~^~~~~~
a.cc:10:10: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   10 |     if(b == "A"){a = "T"}
      |        ~~^~~~~~
a.cc:10:22: error: invalid conversion from 'const char*' to 'char' [-fpermissive]
   10 |     if(b == "A"){a = "T"}
      |                      ^~~
      |                      |
      |                      const char*
a.cc:10:25: error: expected ';' before '}' token
   10 |     if(b == "A"){a = "T"}
      |                         ^
      |                         ;
a.cc:11:10: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   11 |     if(b == "T"){a = "A"}}
      |        ~~^~~~~~
a.cc:11:22: error: invalid conversion from 'const char*' to 'char' [-fpermissive]
   11 |     if(b == "T"){a = "A"}}
      |                      ^~~
      |                      |
      |                      const char*
a.cc:11:25: error: expected ';' before '}' token
   11 |     if(b == "T"){a = "A"}}
      |                         ^
      |                         ;
a.cc:12:12: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   12 |   elseif(b == "C" || b == "G"){
      |          ~~^~~~~~
a.cc:12:24: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   12 |   elseif(b == "C" || b == "G"){
      |                      ~~^~~~~~
a.cc:12:3: error: 'elseif' was not declared in this scope
   12 |   elseif(b == "C" || b == "G"){
      |   ^~~~~~
a.cc:15:3: error: 'else' without a previous 'if'
   15 |   else {};
      |   ^~~~
Language: C++

#include <iostream>
using namespace std
  
int main{
  char b;
  char a;
  cin >> b;
  
  if(b == "A" || b == "T"){
    if(b == "A"){a = "T"}
    if(b == "T"){a = "A"}}
  elseif(b == "C" || b == "G"){
    if(b == "C"){a = "G"}
    if(b == "G"){a = "C"}}
  else {};
  
  cout << a << endl;
  
  return 0;
}

Compiler output:
a.cc:2:20: error: expected ';' before 'int'
    2 | using namespace std
      |                    ^
      |                    ;
    3 | 
    4 | int main{
      | ~~~                 
a.cc:4:5: error: cannot declare '::main' to be a global variable
    4 | int main{
      |     ^~~~
a.cc:5:3: error: expected primary-expression before 'char'
    5 |   char b;
      |   ^~~~
a.cc:5:3: error: expected '}' before 'char'
a.cc:4:9: note: to match this '{'
    4 | int main{
      |         ^
a.cc:7:3: error: 'cin' does not name a type
    7 |   cin >> b;
      |   ^~~
a.cc:9:3: error: expected unqualified-id before 'if'
    9 |   if(b == "A" || b == "T"){
      |   ^~
a.cc:12:9: error: expected constructor, destructor, or type conversion before '(' token
   12 |   elseif(b == "C" || b == "G"){
      |         ^
a.cc:15:3: error: expected unqualified-id before 'else'
   15 |   else {};
      |   ^~~~
a.cc:17:3: error: 'cout' does not name a type
   17 |   cout << a << endl;
      |   ^~~~
a.cc:19:3: error: expected unqualified-id before 'return'
   19 |   return 0;
      |   ^~~~~~
a.cc:20:1: error: expected declaration before '}' token
   20 | }
      | ^
Language: C++

#include <iostream>
using namespace std
  
int main{
  char b;
  char a;
  cin >> b;
  
  if(b == "A" || b == "T"){
    if(b == "A"){a = "T"}
    if(b == "T"){a = "A"}}
  elseif(b == "C" || b == "G"){
    if(b == "C"){a = "G"}
    if(b == "G"){a = "C"}}
  else {};
  
  cout << a << endl;
}

Compiler output:
a.cc:2:20: error: expected ';' before 'int'
    2 | using namespace std
      |                    ^
      |                    ;
    3 | 
    4 | int main{
      | ~~~                 
a.cc:4:5: error: cannot declare '::main' to be a global variable
    4 | int main{
      |     ^~~~
a.cc:5:3: error: expected primary-expression before 'char'
    5 |   char b;
      |   ^~~~
a.cc:5:3: error: expected '}' before 'char'
a.cc:4:9: note: to match this '{'
    4 | int main{
      |         ^
a.cc:7:3: error: 'cin' does not name a type
    7 |   cin >> b;
      |   ^~~
a.cc:9:3: error: expected unqualified-id before 'if'
    9 |   if(b == "A" || b == "T"){
      |   ^~
a.cc:12:9: error: expected constructor, destructor, or type conversion before '(' token
   12 |   elseif(b == "C" || b == "G"){
      |         ^
a.cc:15:3: error: expected unqualified-id before 'else'
   15 |   else {};
      |   ^~~~
a.cc:17:3: error: 'cout' does not name a type
   17 |   cout << a << endl;
      |   ^~~~
a.cc:18:1: error: expected declaration before '}' token
   18 | }
      | ^
Language: C

#include <stdio.h>
#include <string.h>

int main() {

  char a[];

  scanf("%s", a);
  if (strcmp(a, "A") == 0 ) {
    printf("T");
  } else if (strcmp(a, "C") == 0) {
    printf("G");
  } else if (strcmp(a, "G") == 0) {
    printf("C");
  } else {
    printf("A");
  }
  return 0;
}

Compiler output:
main.c: In function 'main':
main.c:6:8: error: array size missing in 'a'
    6 |   char a[];
      |        ^
Language: C

#include <stdio.h>
#include <string.h>

int main() {

  char a[];

  scanf("%c", a);
  if (strcmp(a, "A") == 0 ) {
    printf("T");
  } else if (strcmp(a, "C") == 0) {
    printf("G");
  } else if (strcmp(a, "G") == 0) {
    printf("C");
  } else {
    printf("A");
  }
  return 0;
}

Compiler output:
main.c: In function 'main':
main.c:6:8: error: array size missing in 'a'
    6 |   char a[];
      |        ^
Language: C

#include <stdio.h>
#include <string.h>

int main {
  
  char a;
  
  scanf("%c", &a);
  if (strcmp(a, 'A') == 0 ) {
    printf("T");
  } else if (strcmp(a, 'C') == 0) {
    printf("G");
  } else if (strcmp(a, 'G') == 0) {
    printf("C");
  } else {
    printf("A");
  }
  return 0;
}

Compiler output:
main.c:4:10: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
    4 | int main {
      |          ^
Language: C++

#include <iostream>
using namespace std;

int main(){
  string a[4]=["A","C","G","T"];
  string s;
  cin >> s;
  for(int i=0;i<4;i++){
    if(s==a[i]){
      cout << a[3-i] << endl;
    }
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:16: error: expected identifier before string constant
    5 |   string a[4]=["A","C","G","T"];
      |                ^~~
a.cc:5:19: error: expected ']' before ',' token
    5 |   string a[4]=["A","C","G","T"];
      |                   ^
      |                   ]
a.cc: In lambda function:
a.cc:5:19: error: expected '{' before ',' token
a.cc: In function 'int main()':
a.cc:5:15: error: array must be initialized with a brace-enclosed initializer
    5 |   string a[4]=["A","C","G","T"];
      |               ^~~~
a.cc:5:20: error: expected unqualified-id before string constant
    5 |   string a[4]=["A","C","G","T"];
      |                    ^~~
Language: C++

#include <iostream>
using namespace std;

int main(){
  string a[]=["A","C","G","T"];
  string s;
  cin >> s;
  for(int i=0;i<4;i++){
    if(s==a[i]){
      cout << a[3-i] << endl;
    }
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:15: error: expected identifier before string constant
    5 |   string a[]=["A","C","G","T"];
      |               ^~~
a.cc:5:18: error: expected ']' before ',' token
    5 |   string a[]=["A","C","G","T"];
      |                  ^
      |                  ]
a.cc: In lambda function:
a.cc:5:18: error: expected '{' before ',' token
a.cc: In function 'int main()':
a.cc:5:14: error: initializer fails to determine size of 'a'
    5 |   string a[]=["A","C","G","T"];
      |              ^~~~
a.cc:5:14: error: array must be initialized with a brace-enclosed initializer
a.cc:5:19: error: expected unqualified-id before string constant
    5 |   string a[]=["A","C","G","T"];
      |                   ^~~
Language: Java

import java.util.Scanner;

public class Main{
  static String str; 
  public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    str = sc.next();
    if(str=="A"){
      System.out.println(T);
    }
    else if(str=="T"){
		System.out.println(A);
    }
    else if(str=="G"){
      System.out.println(C);
    }
    else {
      System.out.println(G);
    }
  }
}
    

Compiler output:
Main.java:9: error: cannot find symbol
      System.out.println(T);
                         ^
  symbol:   variable T
  location: class Main
Main.java:12: error: cannot find symbol
		System.out.println(A);
		                   ^
  symbol:   variable A
  location: class Main
Main.java:15: error: cannot find symbol
      System.out.println(C);
                         ^
  symbol:   variable C
  location: class Main
Main.java:18: error: cannot find symbol
      System.out.println(G);
                         ^
  symbol:   variable G
  location: class Main
4 errors
Language: C

#include<stdio.h>

int main(){
  char a;
  scanf("%c\n",&a);
  if(a=='A')
    printf("T");
  else if(a=='T')
    printf("A");
  else if(a=='C');
    plintf("G");
  else if(a=='G');
    printf("C");
}

Compiler output:
main.c: In function 'main':
main.c:11:5: error: implicit declaration of function 'plintf'; did you mean 'printf'? [-Wimplicit-function-declaration]
   11 |     plintf("G");
      |     ^~~~~~
      |     printf
main.c:12:3: error: 'else' without a previous 'if'
   12 |   else if(a=='G');
      |   ^~~~