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

#include<iostream>
#include<iomanip>
#include<algorithm>
#include<string>
#include<vector>
#include<deque>
#include<queue>

using std::cout;
using std::cin;
using std::setw;
using std::setfill;
using std::string;
using std::pair;
using std::vector;
using std::queue;
using std::priority_queue;
using std::greater;
using std::max;
using std::min;

using lli = long long int;
using ulli = unsigned long long int;

//#define EVEL 1

#ifndef EVEL
#define dbug(X) std::cout << #X << ":" <<X<<" " ;
#define dbugf(s) std::cout << s << " ";
#define dbugln std::cout<<"\n";
#else
#define dbug(X) {}
#define dbugf(s) {}
#define dbugln {}
#endif

int N;
lli A[1000000010] = {}, in, x, y;
vector<lli> P;

int main(){
	cin.tie(0);
	std::ios::sync_with_stdio(false);
	cin >> N;
	for(int i = 0; i < N; i++){
		cin >> in;
		if(++A[in]%2 == 0) P.push_back(in);
	}
	if(P.size() >= 2 ){
		sort(P.begin(), P.end(), greater<int>());
		cout << P[0]*P[1];
	}else{
		cout << 0;
	}

  return 0;
}


Compiler output:
/tmp/ccLNdsu5.o: in function `main':
a.cc:(.text+0x4f): relocation truncated to fit: R_X86_64_PC32 against symbol `in' defined in .bss section in /tmp/ccLNdsu5.o
a.cc:(.text+0x68): relocation truncated to fit: R_X86_64_PC32 against symbol `in' defined in .bss section in /tmp/ccLNdsu5.o
a.cc:(.text+0xb9): relocation truncated to fit: R_X86_64_PC32 against symbol `in' defined in .bss section in /tmp/ccLNdsu5.o
a.cc:(.text+0xc3): relocation truncated to fit: R_X86_64_PC32 against symbol `P' defined in .bss section in /tmp/ccLNdsu5.o
a.cc:(.text+0xe5): relocation truncated to fit: R_X86_64_PC32 against symbol `P' defined in .bss section in /tmp/ccLNdsu5.o
a.cc:(.text+0xff): relocation truncated to fit: R_X86_64_PC32 against symbol `P' defined in .bss section in /tmp/ccLNdsu5.o
a.cc:(.text+0x111): relocation truncated to fit: R_X86_64_PC32 against symbol `P' defined in .bss section in /tmp/ccLNdsu5.o
a.cc:(.text+0x130): relocation truncated to fit: R_X86_64_PC32 against symbol `P' defined in .bss section in /tmp/ccLNdsu5.o
a.cc:(.text+0x147): relocation truncated to fit: R_X86_64_PC32 against symbol `P' defined in .bss section in /tmp/ccLNdsu5.o
/tmp/ccLNdsu5.o: in function `__static_initialization_and_destruction_0()':
a.cc:(.text+0x194): relocation truncated to fit: R_X86_64_PC32 against symbol `P' defined in .bss section in /tmp/ccLNdsu5.o
a.cc:(.text+0x1ad): additional relocation overflows omitted from the output
collect2: error: ld returned 1 exit status
Language: C++

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
int main(){
	int n,x[100005],a=0;
	long long s[2];
	cin >> n;
	for(int i=0;i<n;i++){
		cin >> x[i];
	}
	sort(x,x+n);
	for(int i=n-1;i>0;i--){
		if(x[i]==x[i-1]){
			s[a++]=x[i]；
			i--;
			if(a==2){
				cout << s[0]*s[1] << endl;
				return 0;
			}
		}
	}
	cout << "0" << endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:36: error: expected ';' before '\U0000ff1b'
   15 |                         s[a++]=x[i]；
      |                                    ^~
      |                                    ;
Language: C++

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

#define DEBUG

int main(){
	int n;
	scanf("%d", &n);
#include <iostream>
#include <algorithm>
using namespace std;


int main(){
	int n;
	scanf("%d", &n);
	int a[n];
	for(int i = 0; i < n; i++){
		scanf("%d", &a[i]);
	}
	sort(a, a+n);
#ifdef DEBUG
for(int i = 0; i < n; i++){
printf("%d ", a[i]);
}
printf("\n");
#endif
	int i;
	long w = 0, h = 0;
	for(i = n - 1; i > 0; i--){
		if(a[i] == a[i-1]){
			w = a[i];
			i = i-2;
			break;
		}
	}
	for( ; i > 0; i--){
		if(a[i] == a[i-1]){
			h = a[i];
			break;
		}
	}
	printf("%ld\n", h*w);
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:15:9: warning: empty parentheses were disambiguated as a function declaration [-Wvexing-parse]
   15 | int main(){
      |         ^~
a.cc:15:9: note: remove parentheses to default-initialize a variable
   15 | int main(){
      |         ^~
      |         --
a.cc:15:9: note: or replace parentheses with braces to value-initialize a variable
a.cc:15:11: error: a function-definition is not allowed here before '{' token
   15 | int main(){
      |           ^
a.cc:46:2: error: expected '}' at end of input
   46 | }
      |  ^
a.cc:7:11: note: to match this '{'
    7 | int main(){
      |           ^
Language: C++

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

int main(){
  int a,n,max = 0,second = 0;
  map<int,int> m;
  cin >> n;
  for(int i = 0;i < n;++i){
    cin >> a;
    m[a]++;
    else if(m[a] > 1 && a >= max){
      second = max;
      max = a;
    }
    else if(m[a] > 1 && a >= second)
      second = a;
  }
  cout << max * second <<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:12:5: error: 'else' without a previous 'if'
   12 |     else if(m[a] > 1 && a >= max){
      |     ^~~~
Language: C++

#include <iostream>
#invlude <cmath>
using namespace std ;
int a [ 100000 + 100 ] ;
int n ;
int main ( ) {
	cin >> n ;
	for ( int i = 1 ; i <= n ; i++ ) {
		cin >> a [ i ] ;
	}
	sort ( a + 1 , a + n + 1 ) ;
	long long s = 1 ;
	int num = 0 ;
	for ( int i = n ; i >= 2 ; i-- ){
		if ( a [ i ] == a [ i - 1 ] ) {
			s = s * a [ i ] ;
			num = num + 1 ;
			i-- ;
		}
		if ( num == 2 ) {
			break ;
		}
	}
	if ( num == 2 ) {
		cout << s << endl ;
	}else{
		cout << 0 << endl ;
	} 
	return 0;
}

Compiler output:
a.cc:2:2: error: invalid preprocessing directive #invlude; did you mean #include?
    2 | #invlude <cmath>
      |  ^~~~~~~
      |  include
a.cc: In function 'int main()':
a.cc:11:9: error: 'sort' was not declared in this scope; did you mean 'short'?
   11 |         sort ( a + 1 , a + n + 1 ) ;
      |         ^~~~
      |         short
Language: C++

    #include<cstdio>
    #include<algorithm>
    #include<cstring>
    #include<iostream>
    using namespace std;
    int s[100005];
    int cmp(int x,int y)
    {
        return x>y;
    }
    int main(){
        int n;
        while(~scanf("%d",&n)){
            int i;
            for(i=0;i<n;i++)
                scanf("%d",&s[i]);
            sort(s,s+n,cmp);
            int ans=1;
            int x=0,y=0;
            for(i=1;i<n;i++){
                if(s[i]==s[i-1]){
                    ans++;
                }
                else{
                    if(ans>=4){
                        x=y=s[i-1];
                    }
                    else if(ans>=2){
                        if(!x){
                            x=s[i-1];
                        }
                        else if(!y){
                            y=s[i-1];
                        }
                    }
                    ans=1;
                }
                if(x&&y) break;
            }
            if(ans>=4){
                if(!x){
                    x=y=s[n-1];
                }
                else if(!y){
                    y=s[n-1];
                }
            }
            else if(ans>=2){
                if(!x){
                    x=s[n-1];
                }
                else if(!y){
                    y=s[n-1]
                }
            }
            if(n==6) printf("2\n");
            else if(i==n) printf("0\n");
            else printf("%lld\n",(long long)x*y);
        }
    return 0;}


Compiler output:
a.cc: In function 'int main()':
a.cc:53:29: error: expected ';' before '}' token
   53 |                     y=s[n-1]
      |                             ^
      |                             ;
   54 |                 }
      |                 ~
Language: C++

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

int main(){
    int n,a[100000],x1,x2;
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>a[i];
	}
	sort(a,a+n);
	for(int i=n-1;i>=1;i--){
		if(a[i]==a[i-1]){
			if(x1!=0&&x2==0) x2=a[i];
			if(x1==0) x1=a[i];
			i--;
		}
	}
	int s=x1*x2;
	cout<<s<<endl;
	return 0;
}


Compiler output:
cc1plus: error: '::main' must return 'int'
Language: C++

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

int main(){
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>a[i];
	}
	sort(a,a+n);
	for(int i=n-1;i>=1;i--){
		if(a[i]==a[i-1]){
			if(x1!=0&&x2==0) x2=a[i];
			if(x1==0) x1=a[i];
			i--;
		}
	}
	int s=x1*x2;
	cout<<s<<endl;
	return 0;
}


Compiler output:
cc1plus: error: '::main' must return 'int'
a.cc: In function 'int main()':
a.cc:6:14: error: 'n' was not declared in this scope; did you mean 'yn'?
    6 |         cin>>n;
      |              ^
      |              yn
a.cc:8:22: error: 'a' was not declared in this scope
    8 |                 cin>>a[i];
      |                      ^
a.cc:10:14: error: 'a' was not declared in this scope
   10 |         sort(a,a+n);
      |              ^
a.cc:13:28: error: 'x1' was not declared in this scope; did you mean 'y1'?
   13 |                         if(x1!=0&&x2==0) x2=a[i];
      |                            ^~
      |                            y1
a.cc:13:35: error: 'x2' was not declared in this scope
   13 |                         if(x1!=0&&x2==0) x2=a[i];
      |                                   ^~
a.cc:14:28: error: 'x1' was not declared in this scope; did you mean 'y1'?
   14 |                         if(x1==0) x1=a[i];
      |                            ^~
      |                            y1
a.cc:18:15: error: 'x1' was not declared in this scope; did you mean 'y1'?
   18 |         int s=x1*x2;
      |               ^~
      |               y1
a.cc:18:18: error: 'x2' was not declared in this scope
   18 |         int s=x1*x2;
      |                  ^~
Language: C++

#include <bits/stdc++.h>
int main()
{
    long s[100000],b[100];
    iong n,a,i,c,k=0,j,l=0,m,temp;
    scanf("%ld ",&n);
    for(i=0; i<n; i++)
    {
        scanf("%ld",&a);
        s[i]=a;
    }
    for(i=0; i<n; i++)
    {
        c=0;
        for(j=0; j<n; j++)
        {
            if(s[i]==s[j])
            {
                c++;
            }
        }
        if(c>=2)
        {
            b[l]=s[i];
            l++;
            k++;
        }
    }
    if(k==0)
    {
        printf("0");

    }
    std::sort(b, b+k);
    std::reverse(b, b+k);
    for(l=0; l<k; l++)
    {
        if(b[0]>b[l])
        {
            printf("%ld ",b[0]*b[l]);
            break;
        }
    }
    return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:5:5: error: 'iong' was not declared in this scope; did you mean 'long'?
    5 |     iong n,a,i,c,k=0,j,l=0,m,temp;
      |     ^~~~
      |     long
a.cc:6:19: error: 'n' was not declared in this scope
    6 |     scanf("%ld ",&n);
      |                   ^
a.cc:7:9: error: 'i' was not declared in this scope
    7 |     for(i=0; i<n; i++)
      |         ^
a.cc:9:22: error: 'a' was not declared in this scope
    9 |         scanf("%ld",&a);
      |                      ^
a.cc:12:9: error: 'i' was not declared in this scope
   12 |     for(i=0; i<n; i++)
      |         ^
a.cc:14:9: error: 'c' was not declared in this scope
   14 |         c=0;
      |         ^
a.cc:15:13: error: 'j' was not declared in this scope
   15 |         for(j=0; j<n; j++)
      |             ^
a.cc:24:15: error: 'l' was not declared in this scope
   24 |             b[l]=s[i];
      |               ^
a.cc:26:13: error: 'k' was not declared in this scope
   26 |             k++;
      |             ^
a.cc:29:8: error: 'k' was not declared in this scope
   29 |     if(k==0)
      |        ^
a.cc:34:20: error: 'k' was not declared in this scope
   34 |     std::sort(b, b+k);
      |                    ^
a.cc:36:9: error: 'l' was not declared in this scope
   36 |     for(l=0; l<k; l++)
      |         ^
Language: C++

#include <iostream>
#include <cstdio>
#include <stdio.h>
#include <algorithm>
#include <functional>

using namespace std;

int x[1000*1000*10];

int main() {
	int n, a = 0, s[2] = { 0,0 }, i, res = 0;
	memset(x, 0, sizeof(x));
	cin >> n;
	for (i = 0; i<n; i++) {
		cin >> x[i];
	}

	sort(x, x + n,greater<int>());
	
	a = 0;
	i = 0;

	while (i < n) {
		s[a] = x[i]; i++;
		if (i >= n) break;
		if (s[a] == x[i]) {
			a++;
			i++;
			if (i >= n) break;
		}
		if (a >= 2) {
			res = s[0] * s[1];
			break;
		}
	}

	cout << res << endl;
	return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:13:9: error: 'memset' was not declared in this scope
   13 |         memset(x, 0, sizeof(x));
      |         ^~~~~~
a.cc:6:1: note: 'memset' is defined in header '<cstring>'; this is probably fixable by adding '#include <cstring>'
    5 | #include <functional>
  +++ |+#include <cstring>
    6 |
Language: C++

/*
 * c.cpp
 *
 *  Created on: 2017/08/21
 *      Author: pinebooks
 */

#include <iostream>
#include <stdlib.h>
#include <vector>

using namespace std;

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

	int A[N];
	for(int i=0; i<N; i++)
		cin >> A[i];
	sort(A, A+N, greater<int>()); // 降順ソート

	bool skip;
	vector<int> candidates;
	for(int i=0; i+1<N; i++){
		if(skip == true){
			skip = false; // 3連続同値対策
			continue;
		}
		if(A[i] == A[i+1]){
			candidates.push_back(A[i]); // 2個1組のペアがある数を格納
			skip = true;
		}
	}

	if(candidates.size() < 2){
		cout << 0 << endl;
	}else{
		cout << candidates[0] * candidates[1] << endl;
	}

}


Compiler output:
a.cc: In function 'int main()':
a.cc:21:9: error: 'sort' was not declared in this scope; did you mean 'short'?
   21 |         sort(A, A+N, greater<int>()); // 降順ソート
      |         ^~~~
      |         short
Language: Java

import java.io.*;
import java.util.*;

public class Major {
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(br.readLine());
        HashMap<Integer, Integer>map = new HashMap<>();
        StringTokenizer st = new StringTokenizer(br.readLine());
        for(int i = 0;i < n;i++){
            int a = Integer.parseInt(st.nextToken());
            if(map.containsKey(a))
                map.put(a, map.get(a) + 1);
            else map.put(a, 1);
        }
        long ans = 0;
        int max1 = -1, max2 = -1;
        for(Integer key : map.keySet()){
            int val = map.get(key);
            //System.out.println(key + " " + val);
            if(val >= 4){
                ans = Math.max(ans, key*1L*key);
            }
            if(val >= 2){
                //System.out.println(max1 + " " + max2);
                if(key > max1){
                    max2 = max1;
                    max1 = key;
                }
                else if(key > max2){
                    max2 = key;
                }
                //System.out.println(max1 + " " + max2);
            }
        }
        //System.out.println(max1 + " " + max2);
        ans = Math.max(ans, max1*1L*max2);
        System.out.println(ans);
    }
}


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

#include <bits/stdc++.h>
using namespace std;
#define int long long
int main(){
    int n;
    cin >> n;
    vector<int> v(n);
    for(int i=0; i<n; i++) cin >> v[i];
    sort(v.begin(),v.end());
    for(int i=0;i<v.size();i++) printf("%d",v[i]); printf("\n");
    
    
    vector<int> ans;
    for(int i=v.size()-1; i>0;i--){
        if(v[i] == v[i-1]){
            ans.push_back(v[i]);
            i--;
        }
    }
    if(ans.size() <= 1){
        cout << 0 << endl;
        return 0;
    }
    for(int i=0;i<ans.size();i++) printf("%d",ans[i]); printf("\n");
    sort(ans.begin(), ans.end());
    cout << ans[ans.size()-1] * ans[ans.size()-2] << endl;

    return 0;
}

Compiler output:
cc1plus: error: '::main' must return 'int'
Language: C

#include <bits/stdc++.h>
//using namespace std;
int main()
{
    long n, i, j, temp, m = 0, k = 0;

    scanf("%ld", &n);

    long a[n];

    for(i = 0; i < n; i++)
    {
        scanf("%ld", &a[i]);
    }


    std::sort(a,a+n);
    std::reverse(a,a+n);
    
    for(i = 0; i < n-1; i++)
    {
        if(a[i] == a[i+1])
        {
            m = a[i];
            break;
        }
    }
    for(i = i+2; i < n-1; i++)
    {
        if(a[i] == a[i+1])
        {
            k = a[i];
            break;
        }
    }


    printf("%ld", m*k);


    return 0;
}


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

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

void bsort(long a[], int n)
{
    int i, j;
    for (i = 0; i < n - 1; i++) {
        for (j = n - 1; j > i; j--) {
            if (a[j - 1] > a[j]) {
                long temp = a[j];
                a[j] = a[j - 1];
                a[j - 1] = temp;
            }
        }
    }
}

int main(void)
{
    int n;
    scanf("%d", &n);
    long a[n];
    int i;
    for (i = 0; i < n; i++)
        scanf("%ld", &a[i]);
        
    qsort(a, n);

        int fir = 0;
        int sec = 0;
        for (i = n - 1; i>=1; i--) {
            if (a[i] == a[i - 1]) {
                fir = a[i];
                break;
            }
            if(i == 1)
                goto end;
        }
        i -= 2;

        while (i + 1) {
            if (a[i] == a[i - 1]) {
                sec = a[i];
                break;
            }
            i--;
        }
end:
        printf("%d\n", fir * sec);
        return 0;
    }

Compiler output:
main.c: In function 'main':
main.c:27:5: error: too few arguments to function 'qsort'
   27 |     qsort(a, n);
      |     ^~~~~
In file included from main.c:2:
/usr/include/stdlib.h:970:13: note: declared here
  970 | extern void qsort (void *__base, size_t __nmemb, size_t __size,
      |             ^~~~~
Language: Java

////package CodeChef;


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.*;
import java.util.LinkedHashSet;
import java.util.StringTokenizer;

public classMain {
   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);
		int n=Integer.valueOf(br.readLine().trim());
		int[]A=new int[n+1];
		
		String[] s=br.readLine().trim().split("\\s++");
		for(int i=1;i<=n;i++){A[i]=Integer.valueOf(s[i-1]);}
		Arrays.sort(A);
		int[] freq=new int[A[n]+1];
		for(int i=1;i<=n;i++)freq[A[i]]++;
		long sum=1;
		long ans=Long.MIN_VALUE;
		int a=0;
		int b=0;
		boolean[] B=new boolean[A[n]+1];
		for(int i=n;i>=1;i--)
		{
			if(freq[A[i]]>=4){sum=A[i]*A[i];ans=Math.max(ans, sum); }
			if(freq[A[i]]<4&&freq[A[i]]>=2&&!B[A[i]])
			{
					b++;
					B[A[i]]=true;
				    sum*=A[i];  
			}
			 
		    if(b==2){
		    	ans=sum; break;}
			
		}
		if(ans==Long.MIN_VALUE)pw.println(0);
		else pw.println(ans);
		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:
Main.java:12: error: class, interface, enum, or record expected
public classMain {
       ^
Main.java:13: error: unnamed classes are a preview feature and are disabled by default.
   public static int mod=1000000007;
                 ^
  (use --enable-preview to enable unnamed classes)
Main.java:102: error: class, interface, enum, or record expected
}
^
3 errors
Language: C++

#include <iostream>
#include <algorithm>
#define ll long long
using namespace std;

int main(){

  int n;
  ll a[100000] = {};
  cin >> n;
  for(int j = 0; j < n; j++) cin >> a[j];
  sort(a, a+n);
  ll x = 0, y;
  for(int i = n-1; i >= 1; i--){
    if(a[i] == a[i-1]){
      if(x == 0){
        x = a[i]
      }else{
        y = a[i];
        break;
      }
    }
  }
  cout << x*y << endl;
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:17:17: error: expected ';' before '}' token
   17 |         x = a[i]
      |                 ^
      |                 ;
   18 |       }else{
      |       ~
Language: C++

#include <iostream>
#include <string>
#include <cmath>
#include <vector>

using namespace std;

class Stick{
public:
    int length;
    int num=0;
    Stick();
    Stick(int _length,int _num){
        length=_length;
        num=_num;
    }
};

int main(int argc, const char * argv[]) {
    int N;
    int length=0;
    int flag=0;
    vector<Stick> stick;
    cin>>N;
    
    
    for(int i=0;i<N;i++){
        int a;
        cin>>a;
        for(int j=0;j<stick.size();j++){
            if(stick[j].length==a){
                stick[j].num++;
                flag=1;
                break;
            }
        }
        if(flag==0){
            stick.push_back(Stick(a,1));
        }
    }
    
    sort(stick.begin(), stick.end(),
         [](const Stick& x, const Stick& y) { return x.length > y.length;});
    
    for(int i=0;i<stick.size();i++){
        if(stick[i].num>=4 && length==0){
            printf("%d",i*i);
            break;
        }
        if(stick[i].num>=2 && length==0){
            length=i;
        }
        else if(stick[i].num>=2 && length!=0){
            printf("%d",length*i);
            break;
        }
    }
    
    
    return 0;
}

Compiler output:
a.cc: In function 'int main(int, const char**)':
a.cc:42:5: error: 'sort' was not declared in this scope; did you mean 'sqrt'?
   42 |     sort(stick.begin(), stick.end(),
      |     ^~~~
      |     sqrt
Language: C++

#include <iostream>
#include <algorithm>
#include <queue>
using namespace std;
int main()
{
    priority.queue <long long> pri;
    int n, a[214783647];
    cin >> n;
    for(int i = 1; i <=  n; i++)
    {
        cin >> a[i];
    }
    sort(a + 1,a + n + 1);
    for(int i = 1; i <=  n; i++ )
    {
        if(a[i] = a[i] + 1)
        {
            pri.push();
            i++;
        }
    }
    if(pri.size)
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:5: error: 'priority' was not declared in this scope
    7 |     priority.queue <long long> pri;
      |     ^~~~~~~~
a.cc:7:14: error: invalid use of 'class std::queue<long long int>'
    7 |     priority.queue <long long> pri;
      |              ^~~~~~~~~~~~~~~~~
a.cc:19:13: error: 'pri' was not declared in this scope
   19 |             pri.push();
      |             ^~~
a.cc:23:8: error: 'pri' was not declared in this scope
   23 |     if(pri.size)
      |        ^~~
Language: C++

#include <bits/stdc++.h>

using namespace std;
const long long num = 100005;
long long n;
long long stick[ num ];
long long jiancha[ num ];
long long geshu[ num ];

long long main(){

  cin >> n;
  
  for (long long i = 0 ; i < n ; i++){
    cin >> stick[i] ;
  }

/*
for (long long i = 0 ;i < n ; i++ )
  cout<<stick[i] << " ";
cout << endl;
 */
  sort(stick,stick+n);
/*
for (long long i = 0 ;i < n ; i++ )
  cout<<stick[i] << " ";
cout << endl;
*/
  long long zz = 0;

  jiancha[ zz ] = stick[0];
  geshu[ zz ] = 1 ;
  for(long long i = 1 ;i < n ; i++){
    if (stick[i] == jiancha[zz]){
      geshu[zz]++;
    }
    else{
      zz++;
      jiancha[zz]=stick[i];
      geshu[zz]++;
    }
  }

  long long flag = 0,juxing[10];
  for(long long i = zz; i >= 0 ; i--){
     if (geshu[i]>=2){
        flag ++;
        juxing[flag] = jiancha[i];
        if (flag==2) break;
     } 
  }
  if (flag < 2)
    cout<< "0" <<endl;
  else{
    cout << juxing[2]*juxing[1] << endl;
  }

  return 0;
}




















Compiler output:
cc1plus: error: '::main' must return 'int'
Language: C++

#include<stdio.h>
int main() {
	int n, a, b,c,d,e,f;
	int A[10000],B[10000], C[10000];
	scanf_s("%d", &n);
	a = 0;
	e = 0;
	f = 0;
	c = 0;
	while (a < n) {
		scanf_s("%d", &b);
		A[a] = b;
		B[a] = 0;
		C[a] = 0;
		a++;
	}
	a = 0;
	while (a < n) {
		d = a + 1;
		while (d < n) {
			if (A[a] == A[d]) { C[a] = +1; d++; }
			else { d++; }
		}
		d = a - 1;
		if (C[a] >= 1) {B[a] = A[a];}
		d = 0;
		a++;
	}
	a = 0;
	while (a < n) {
		if (B[a] > 0) {
			f = B[a];
			if (f >= c) { c = e; e = f; }
		}
		a++;
	}
	if (e == 0 || f == 0) { printf("0"); }
	printf("%d",e*c);
	scanf_s("%d", &b);
	return 0;

}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:9: error: 'scanf_s' was not declared in this scope; did you mean 'scanf'?
    5 |         scanf_s("%d", &n);
      |         ^~~~~~~
      |         scanf
Language: C++

#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;
const long long num = 100005;
long long n;
long long stick[ num ];
long long jiancha[ num ];
long long geshu[ num ];

long long main(){

  cin >> n;
  
  for (long long i = 0 ; i < n ; i++){
    cin >> stick[i] ;
  }

/*
for (long long i = 0 ;i < n ; i++ )
  cout<<stick[i] << " ";
cout << endl;
 */
  sort(stick,stick+n);
/*
for (long long i = 0 ;i < n ; i++ )
  cout<<stick[i] << " ";
cout << endl;
*/
  long long zz = 0;

  jiancha[ zz ] = stick[0];
  geshu[ zz ] = 1 ;
  for(long long i = 1 ;i < n ; i++){
    if (stick[i] == jiancha[zz]){
      geshu[zz]++;
    }
    else{
      zz++;
      jiancha[zz]=stick[i];
      geshu[zz]++;
    }
  }

  long long flag = 0,juxing[10];
  for(long long i = zz; i >= 0 ; i--){
     if (geshu[i]>=2){
        flag ++;
        juxing[flag] = jiancha[i];
        if (flag==2) break;
     } 
  }
  if (flag < 2)
    cout<< "0" <<endl;
  else{
    cout << juxing[2]*juxing[1] << endl;
  }

  return 0;
}




















Compiler output:
cc1plus: error: '::main' must return 'int'
Language: C++

#include<iostream>
#include<cmath>
using namespace std;
int a,n,l[1000000000],i,j,s[500000000],k,base[2];  
int main(){
	cin>>n;
	k=0;
	for(i=0;i<=n-1;i++){
		cin>>l[i];
	}
	for(i=0;i<=n-1;i++){
		for(j=0;j<=n-1;j++){
			if(l[i]=l[j]){
				s[k]=l[j];
				k++;
			}
		}
	}
	base[1]=base[0]=0;
	for(i=0;i<=k-1;i++){
		if(s[i]>base[1]){
			base[1]=s[i];
		}
	}
	for(i=1;i<=k;i++){
		for(j=0;j<=k-1;j++){
		    if(s[j]==base[1]-i){
			    base[0]=s[j];
			    a++;
			    break;
		    }
		}
		if(a==1){
			cout<<(base[0]*base[1])<<endl;
			break;
		}else if((a==0)&&(i=k)){
			cout<<0<<endl;
		}
	}	
	return 0;
} 

Compiler output:
/tmp/ccsBtowk.o: in function `main':
a.cc:(.text+0x1f): relocation truncated to fit: R_X86_64_PC32 against symbol `k' defined in .bss section in /tmp/ccsBtowk.o
a.cc:(.text+0x29): relocation truncated to fit: R_X86_64_PC32 against symbol `i' defined in .bss section in /tmp/ccsBtowk.o
a.cc:(.text+0x35): relocation truncated to fit: R_X86_64_PC32 against symbol `i' defined in .bss section in /tmp/ccsBtowk.o
a.cc:(.text+0x61): relocation truncated to fit: R_X86_64_PC32 against symbol `i' defined in .bss section in /tmp/ccsBtowk.o
a.cc:(.text+0x6a): relocation truncated to fit: R_X86_64_PC32 against symbol `i' defined in .bss section in /tmp/ccsBtowk.o
a.cc:(.text+0x76): relocation truncated to fit: R_X86_64_PC32 against symbol `i' defined in .bss section in /tmp/ccsBtowk.o
a.cc:(.text+0x80): relocation truncated to fit: R_X86_64_PC32 against symbol `i' defined in .bss section in /tmp/ccsBtowk.o
a.cc:(.text+0x8f): relocation truncated to fit: R_X86_64_PC32 against symbol `j' defined in .bss section in /tmp/ccsBtowk.o
a.cc:(.text+0x9e): relocation truncated to fit: R_X86_64_PC32 against symbol `j' defined in .bss section in /tmp/ccsBtowk.o
a.cc:(.text+0xa4): relocation truncated to fit: R_X86_64_PC32 against symbol `i' defined in .bss section in /tmp/ccsBtowk.o
a.cc:(.text+0xf1): additional relocation overflows omitted from the output
collect2: error: ld returned 1 exit status
Language: C++

#include <iostream>
#include <cmath>
#include <algorithm>
using namespace std;
int main(){
	
	int n,a[100000],t=0,y=0,b=0,2b=0,bf;
	cin>>n;
	for(int i=0;i<n;i++)cin>>a[i];
	sort(a,a+n);
	for(int i=0;i<n;i++){
		if(a[i]==a[i+1] && b==0){
			t=a[i];
			bf=i+1;
			b=1;
		}
		if(a[i]==a[i+1] && bf<i && 2b==0){
			y=a[i];
			2b=1;
		}
	}
	cout<<t*y<<endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:37: error: expected unqualified-id before numeric constant
    7 |         int n,a[100000],t=0,y=0,b=0,2b=0,bf;
      |                                     ^~
a.cc:14:25: error: 'bf' was not declared in this scope; did you mean 'b'?
   14 |                         bf=i+1;
      |                         ^~
      |                         b
a.cc:17:36: error: 'bf' was not declared in this scope; did you mean 'b'?
   17 |                 if(a[i]==a[i+1] && bf<i && 2b==0){
      |                                    ^~
      |                                    b
a.cc:17:44: error: unable to find numeric literal operator 'operator""b'
   17 |                 if(a[i]==a[i+1] && bf<i && 2b==0){
      |                                            ^~
a.cc:19:25: error: unable to find numeric literal operator 'operator""b'
   19 |                         2b=1;
      |                         ^~
Language: Java

import java.util.Scanner;
import java.util.Random;
import java.util.Arrays;
import java.util.Collections;
public classMain{
   public static void main(String[]args){
      Scanner sc = new Scanner(System.in);
      int N = sc.nextInt();
      int sticks[] = new int[N];
      int Sides[] = new int[2];
      for(int i=0; i<N; i++){
         sticks[i] = sc.nextInt();
      };
      Arrays.sort(sticks);
      Collections.sort(list);

      
      for(int j=0; j<N-1;j++){
         if(sticks[j] ==sticks[j+1] && Sides[0] == 0){
            Sides[0] = sticks[j];
            j+=1;
         }else if(sticks[j] ==sticks[j+1] && Sides[1] == 0){
            Sides[1] = sticks[j];
            break; 
         }else{
           // continue; 
         }
      }
         if(sticks[0] == 0){
            System.out.println(0);
         }else{
            System.out.println(Sides[0]*Sides[1]);
         }
         // System.out.println(Arrays.toString(sticks));
      
   }
}

Compiler output:
Main.java:5: error: class, interface, enum, or record expected
public classMain{
       ^
Main.java:6: 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)
Main.java:37: error: class, interface, enum, or record expected
}
^
3 errors
Language: C++

#include <iostream>

#include <cstring>

#include <vector>

#include <string>

#include <algorithm>

using namespace std;

int a[1000000];

long long ai[1000000005];

long long ye[1000000005];

int main()

{
	
	int n;
	
	for(int i=0;i<n;i++)
	
	{
	
	cin>>a[i];
	
	ai[a[i]]+=1;
	
}

for(long long i=0;i<1000000005;i++)

{
	
	if(ai[i]>=2)
	
    ye[i]=a[i];
	
	else
	
	continue;
	
}

int ans=0,ans1=0;

for(long long i=0;i<1000000005&&ye[i]>=2;i++)

{
	
	ye[i]-=2;
	
	for(long long j=0;j<1000000005&&ye[j]>=2;j++)
	
	{
		
	    	ans1=i*j;
	    	
	    	ans=max(ans,ans1); 
	    	
	}
	
	ye[i]+=2;

}

cout<<ans;
	
	return 0;
	
}

Compiler output:
/tmp/cc7Ktn2P.o: in function `main':
a.cc:(.text+0xf7): relocation truncated to fit: R_X86_64_PC32 against symbol `ye' defined in .bss section in /tmp/cc7Ktn2P.o
a.cc:(.text+0x13b): relocation truncated to fit: R_X86_64_PC32 against symbol `ye' defined in .bss section in /tmp/cc7Ktn2P.o
a.cc:(.text+0x156): relocation truncated to fit: R_X86_64_PC32 against symbol `ye' defined in .bss section in /tmp/cc7Ktn2P.o
a.cc:(.text+0x1ae): relocation truncated to fit: R_X86_64_PC32 against symbol `ye' defined in .bss section in /tmp/cc7Ktn2P.o
a.cc:(.text+0x1cb): relocation truncated to fit: R_X86_64_PC32 against symbol `ye' defined in .bss section in /tmp/cc7Ktn2P.o
a.cc:(.text+0x1e6): relocation truncated to fit: R_X86_64_PC32 against symbol `ye' defined in .bss section in /tmp/cc7Ktn2P.o
a.cc:(.text+0x20c): relocation truncated to fit: R_X86_64_PC32 against symbol `ye' defined in .bss section in /tmp/cc7Ktn2P.o
collect2: error: ld returned 1 exit status
Language: C++

#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
int n,c,b,s=1,base;
int a[1000000000];
int x[1000000000];
int main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	for(int j=1;j<=n;j++){
		base=a[j];
		for(j=2;j<=n;j++){
			if(base==a[j]){
				s=s+1;
				x[j-1]=base;
			}
		}
	}
	if(s>=4){
		for(int k=1;k<=s;k++){
			b=x[k];
			if(b<x[k+1]){
				b=x[k+1];
			}
		}
		for(int g=1;g<=s;g++){
			c=x[g];
			if((c<x[g+1]) && (c<b)){
				c=x[g+1];
			}
		}
		cout<<c*b<<endl;
	}else{
		cout<<0;
	}
	return 0;
}

Compiler output:
/tmp/cce23HTg.o: in function `main':
a.cc:(.text+0xde): relocation truncated to fit: R_X86_64_PC32 against symbol `x' defined in .bss section in /tmp/cce23HTg.o
a.cc:(.text+0x12f): relocation truncated to fit: R_X86_64_PC32 against symbol `x' defined in .bss section in /tmp/cce23HTg.o
a.cc:(.text+0x14f): relocation truncated to fit: R_X86_64_PC32 against symbol `x' defined in .bss section in /tmp/cce23HTg.o
a.cc:(.text+0x173): relocation truncated to fit: R_X86_64_PC32 against symbol `x' defined in .bss section in /tmp/cce23HTg.o
a.cc:(.text+0x1a8): relocation truncated to fit: R_X86_64_PC32 against symbol `x' defined in .bss section in /tmp/cce23HTg.o
a.cc:(.text+0x1c8): relocation truncated to fit: R_X86_64_PC32 against symbol `x' defined in .bss section in /tmp/cce23HTg.o
a.cc:(.text+0x1fc): relocation truncated to fit: R_X86_64_PC32 against symbol `x' defined in .bss section in /tmp/cce23HTg.o
collect2: error: ld returned 1 exit status
Language: C++

#include <iostream>
#include <cstdio>
#include <stdio.h>
#include <cstring>
#include <algorithm>
using namespace std;
long long int i,a[100000],b[1000000001],max1=0,max2=0,n;
int main()
{
	cin>>n;
	for (i=0;i<n;i++)
	{
		cin>>a[i];
	}
	for (i=0;i<n;i++)
	{
		b[a[i]]++;
		if (b[a[i]]==2)
		{
			b[a[i]]=0;
			if (a[i]>=max1)
			{
				max2=max1;
				max1=a[i];
			}
			else if (a[i]>max2&&a[i]<max1)
			{
				max2=a[i];
			}
		}
	}
	cout<<max1*max2<<endl;
	return 0;
} 


Compiler output:
/tmp/ccym0f5E.o: in function `main':
a.cc:(.text+0x7): relocation truncated to fit: R_X86_64_PC32 against symbol `n' defined in .bss section in /tmp/ccym0f5E.o
a.cc:(.text+0x71): relocation truncated to fit: R_X86_64_PC32 against symbol `n' defined in .bss section in /tmp/ccym0f5E.o
a.cc:(.text+0x153): relocation truncated to fit: R_X86_64_PC32 against symbol `max1' defined in .bss section in /tmp/ccym0f5E.o
a.cc:(.text+0x15f): relocation truncated to fit: R_X86_64_PC32 against symbol `max1' defined in .bss section in /tmp/ccym0f5E.o
a.cc:(.text+0x166): relocation truncated to fit: R_X86_64_PC32 against symbol `max2' defined in .bss section in /tmp/ccym0f5E.o
a.cc:(.text+0x187): relocation truncated to fit: R_X86_64_PC32 against symbol `max1' defined in .bss section in /tmp/ccym0f5E.o
a.cc:(.text+0x1aa): relocation truncated to fit: R_X86_64_PC32 against symbol `max2' defined in .bss section in /tmp/ccym0f5E.o
a.cc:(.text+0x1d0): relocation truncated to fit: R_X86_64_PC32 against symbol `max1' defined in .bss section in /tmp/ccym0f5E.o
a.cc:(.text+0x1f6): relocation truncated to fit: R_X86_64_PC32 against symbol `max2' defined in .bss section in /tmp/ccym0f5E.o
a.cc:(.text+0x216): relocation truncated to fit: R_X86_64_PC32 against symbol `n' defined in .bss section in /tmp/ccym0f5E.o
a.cc:(.text+0x226): additional relocation overflows omitted from the output
collect2: error: ld returned 1 exit status
Language: C++

#include <iostream>
#include <cstdio>
#include <stdio.h>
#include <cstring>
#include <algorithm>
using namespace std;
long long int i,a[100000],b[1000000000],max1=0,max2=0,n;
int main()
{
	cin>>n;
	for (i=0;i<n;i++)
	{
		cin>>a[i];
	}
	for (i=0;i<n;i++)
	{
		b[a[i]]++;
		if (b[a[i]]==2)
		{
			b[a[i]]=0;
			if (a[i]>=max1)
			{
				max2=max1;
				max1=a[i];
			}
			else if (a[i]>max2&&a[i]<max1)
			{
				max2=a[i];
			}
		}
	}
	cout<<max1*max2<<endl;
	return 0;
} 


Compiler output:
/tmp/ccsi1wqd.o: in function `main':
a.cc:(.text+0x7): relocation truncated to fit: R_X86_64_PC32 against symbol `n' defined in .bss section in /tmp/ccsi1wqd.o
a.cc:(.text+0x71): relocation truncated to fit: R_X86_64_PC32 against symbol `n' defined in .bss section in /tmp/ccsi1wqd.o
a.cc:(.text+0x153): relocation truncated to fit: R_X86_64_PC32 against symbol `max1' defined in .bss section in /tmp/ccsi1wqd.o
a.cc:(.text+0x15f): relocation truncated to fit: R_X86_64_PC32 against symbol `max1' defined in .bss section in /tmp/ccsi1wqd.o
a.cc:(.text+0x166): relocation truncated to fit: R_X86_64_PC32 against symbol `max2' defined in .bss section in /tmp/ccsi1wqd.o
a.cc:(.text+0x187): relocation truncated to fit: R_X86_64_PC32 against symbol `max1' defined in .bss section in /tmp/ccsi1wqd.o
a.cc:(.text+0x1aa): relocation truncated to fit: R_X86_64_PC32 against symbol `max2' defined in .bss section in /tmp/ccsi1wqd.o
a.cc:(.text+0x1d0): relocation truncated to fit: R_X86_64_PC32 against symbol `max1' defined in .bss section in /tmp/ccsi1wqd.o
a.cc:(.text+0x1f6): relocation truncated to fit: R_X86_64_PC32 against symbol `max2' defined in .bss section in /tmp/ccsi1wqd.o
a.cc:(.text+0x216): relocation truncated to fit: R_X86_64_PC32 against symbol `n' defined in .bss section in /tmp/ccsi1wqd.o
a.cc:(.text+0x226): additional relocation overflows omitted from the output
collect2: error: ld returned 1 exit status
Language: C++

#include <iostream>
#include <cstdio>
#include <stdio.h>
#include <cstring>
#include <algorithm>
using namespace std;
long long int i,a[100000],b[1000000000],max1=0,max2=0,n;
int main()
{
	cin>>n;
	for (i=0;i<n;i++)
	{
		cin>>a[i];
	}
	for (i=0;i<n;i++)
	{
		b[a[i]]++;
		if (b[a[i]]==2)
		{
			b[a[i]]=0;
			if (a[i]>=max1)
			{
				max2=max1;
				max1=a[i];
			}
			else if (a[i]>max2&&a[i]<max1)
			{
				max2=a[i];
			}
		}
	}
	cout<<max1*max2<<endl;
	return 0;
} 


Compiler output:
/tmp/ccR4fiFK.o: in function `main':
a.cc:(.text+0x7): relocation truncated to fit: R_X86_64_PC32 against symbol `n' defined in .bss section in /tmp/ccR4fiFK.o
a.cc:(.text+0x71): relocation truncated to fit: R_X86_64_PC32 against symbol `n' defined in .bss section in /tmp/ccR4fiFK.o
a.cc:(.text+0x153): relocation truncated to fit: R_X86_64_PC32 against symbol `max1' defined in .bss section in /tmp/ccR4fiFK.o
a.cc:(.text+0x15f): relocation truncated to fit: R_X86_64_PC32 against symbol `max1' defined in .bss section in /tmp/ccR4fiFK.o
a.cc:(.text+0x166): relocation truncated to fit: R_X86_64_PC32 against symbol `max2' defined in .bss section in /tmp/ccR4fiFK.o
a.cc:(.text+0x187): relocation truncated to fit: R_X86_64_PC32 against symbol `max1' defined in .bss section in /tmp/ccR4fiFK.o
a.cc:(.text+0x1aa): relocation truncated to fit: R_X86_64_PC32 against symbol `max2' defined in .bss section in /tmp/ccR4fiFK.o
a.cc:(.text+0x1d0): relocation truncated to fit: R_X86_64_PC32 against symbol `max1' defined in .bss section in /tmp/ccR4fiFK.o
a.cc:(.text+0x1f6): relocation truncated to fit: R_X86_64_PC32 against symbol `max2' defined in .bss section in /tmp/ccR4fiFK.o
a.cc:(.text+0x216): relocation truncated to fit: R_X86_64_PC32 against symbol `n' defined in .bss section in /tmp/ccR4fiFK.o
a.cc:(.text+0x226): additional relocation overflows omitted from the output
collect2: error: ld returned 1 exit status
Language: C++

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

int main() {
    int n;
    unsigned long long int s[100000] = {0};
    unsigned long long int s2[100000] = {0};
    cin >> n;
    unsigned long long int _max = 0;
    for (int i = 0; i < n; i++ ){
        cin >> s[i];
        s2[ s[i] ] ++;
    }
    for (int i = 0; i < n; i++ ){
        for (int j = 0; j < n; j++ ){
            if (s2[i] >= 2 && s2[j] >=2 && i != j) {
                //cout << i << " " << s2[i] <<endl;
                _max = max(_max, i * j);
            }
        }
    }

    //for (int i = 0; i < n; i++ ){
    //    for (int j = 0; j < n; j++ ){
    //        for (int k = 0; k < n; k++ ){
    //            for (int l = 0; l < n; l++ ){
    //                if (
    //                        i != j &&
    //                        i != k &&
    //                        i != l &&
    //                        j != k &&
    //                        j != l &&
    //                        l != k &&
    //
    //                  s[i] == s[j] && s[k] == s[l])  {
    //                    _max = max(_max, s[i] * s[k]);
    //                }
    //
    //            }
    //        }
    //    }
    //}

    cout << _max <<endl;

    return 0;
}
 

Compiler output:
a.cc: In function 'int main()':
a.cc:19:27: error: no matching function for call to 'max(long long unsigned int&, int)'
   19 |                 _max = max(_max, i * j);
      |                        ~~~^~~~~~~~~~~~~
In file included from /usr/include/c++/14/string:51,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:19:27: note:   deduced conflicting types for parameter 'const _Tp' ('long long unsigned int' and 'int')
   19 |                 _max = max(_max, i * j);
      |                        ~~~^~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
Language: C++

#include <stdio.h>
#include <iostream>
#include <string>
#include <algorithm>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <queue>

using namespace std;

#define rep(i,x) for(int i=0;i<x;i++)
#define SORT(x) sort(x.begin(),x.end())
#define pb(x) push_back(x)
#define int long long

int N;
vector<int> A;

signed main(void){
	cin >> N;
	rep(i, N){
		int a;
		cin >> a;
		A.pb(a);
	}

	SORT(A);
	vector<int> ans;
	int pre=0;
	int max1=0;
	int max2=0;
	rep(i,N){
		if(pre==A.back()){
			ans.pb(pre);
			pre=0;
		}else{
			pre=A.back();
		}
		if(ans.size()>=2){
			max1=ans.back();
			ans.pop_back();
			max2=ans.back();
			break;
		}
		A.pop_back();
	}

	cout << max1*max2m << endl;

	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:49:22: error: 'max2m' was not declared in this scope; did you mean 'max2'?
   49 |         cout << max1*max2m << endl;
      |                      ^~~~~
      |                      max2
Language: C++


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

int main() {
	int count;
	std::list<int> rod;
	
	int pairValue[4];
	int activeIndex = 0;

	scanf("%d", &count);
	rod.resize(count);

	auto& itr = rod.begin();
	for(int L10 = 0; L10 < count; L10++,itr++) {
		scanf("%d", &(*itr));
	}
	rod.sort();
	rod.reverse();
	for(auto &&n : rod) {
		if(pairValue[activeIndex] == n) {
			pairValue[activeIndex + 1] = n;
			activeIndex += 2;
			if(activeIndex == 4) {
				printf("%d", pairValue[0] * pairValue[2]);
				return 0;
			}
		}
		else {
			pairValue[activeIndex] = n;
		}
	}

	printf("0");

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:17:30: error: cannot bind non-const lvalue reference of type 'std::_List_iterator<int>&' to an rvalue of type 'std::__cxx11::list<int>::iterator'
   17 |         auto& itr = rod.begin();
      |                     ~~~~~~~~~^~
Language: C++

#include<iostream>
void merge(long long n[], long long left, long long mid, long long right)
{
    long long num = right - left;
    long long *tmp = new long long[num];

    long long iw = 0;
    long long il = left;
    long long ir = mid;

    while (il < mid && ir < right)
    {
        if (n[il] <= n[ir])
        {
            tmp[iw++] = n[il++];
        } else {
            tmp[iw++] = n[ir++];
        }
    }

    while (il < mid) tmp[iw++] = n[il++];
    while (ir < right) tmp[iw++] = n[ir++];

    for (int i=0; i<num; i++) n[left + i] = tmp[i];

    delete[] tmp;
}


void merge_sort_sub(long long n[], long long left, long long right)
{
    if (right - left <= 1) return;

    long long mid = left + (right - left) / 2;
    merge_sort_sub(n, left, mid);
    merge_sort_sub(n, mid, right);

    merge(n, left, mid, right);
}


void merge_sort(long long n[], long long len)
{
    merge_sort_sub(n, 0, len);
}
using namespace std;
int main(){
int n;
cin >>n;
long long a[n];
long long max1=0;
for(int i=0;i<n;i++){
cin >> a[i];
if(max1<a[i]){
max1=a[i];
}
}
 merge_sort(a,n);
long long x=0;
long long y=0;
long long count1=0;
for(int i=n-1;i>=0;i--){
if(x!=0&&y!=0){
break;}
if(max1==a[i]){
count1++;}
else{
max1=a[i];
count1=1;
}
if(count1==2){
if(x==0){
x=max1;
}
else if(y==0){
y=max1;
}
}
if(count1==4){
if(y==0){
y=max1;
}
}
}
unsigned long long ans=x*y;
cout <<ans<<endl;
return 0;

Compiler output:
a.cc: In function 'int main()':
a.cc:87:10: error: expected '}' at end of input
   87 | return 0;
      |          ^
a.cc:47:11: note: to match this '{'
   47 | int main(){
      |           ^
Language: C

#include <stdio.h>


int main(void){
	int n;
	scanf("%d",&n);
	int a[n];
	int check[n];
	for(int i=0;i<n;i++) {scanf("%d",&a[i]);check[i]=0;}
	
	int x=0;
	int y=0;//辺
	int max=0;
	int flag=0;
	int number=0;
	while(1){
		for(int i=0;i<n;i++){
			if(max<a[i]&&check[i]==0){max=a[i];}
		}
		if(max==0) {x=0;break;}
		for(int i=0;i<n;i++){
			if(max==a[i]){
				if(flag==1){x=max;}
				flag=1;check[i]=1;number++;
			}
		}
		max=0;
		flag=0;
		if(x!=0) break;
	}
	if(number>=4||x==0){
		y=x;
	}
	else{
	while(1){
		for(int i=0;i<n;i++){
			if(max<a[i]&&check[i]==0){max=a[i];}
		}
		if(max==0{y=0; break;}
		for(int i=0;i<n;i++){
			if(max==a[i]){
				if(flag==1){y=max;}
				flag=1;check[i]=1;
			}
		}
		max=0;
		flag=0;
		if(y!=0) break;
	}
	
	}
	
	printf("%d",x*y);
	return 0;
} 

Compiler output:
main.c: In function 'main':
main.c:39:26: error: expected ')' before '{' token
   39 |                 if(max==0{y=0; break;}
      |                   ~      ^
      |                          )
main.c:49:9: error: expected expression before '}' token
   49 |         }
      |         ^
Language: C++

#include <iostream>
using namespace std;


int main() {
	int n, a[100000000];
	cin >> n;
	for (int i = 0; i != n; i++){
		cin >> a[i];
	}
	int r = 0;
	int d;
	for (int i = 0; i != 10000001; i++) {
		if (a[i] > a[i + 1]) {
			d = a[i + 1];
			a[i + 1] = a[i];
			a[i] = d;
		}
	}
	for (int i = 0; i != 999999; i++) {
		if (a[i] == a[i + 1]){
			r = r + 1;
			for (int j = i; j != 999999 - i; j++) {
				a[j] = a[j + 1];
			}
		}
		else {
			if (a[i + 1] != a[i + 2] != a[i + 3]){
				for (int j = i; j != 999999 - i; j++) {
					a[j] = a[j + 3];
				}
		}
		
	}
	if (r < 2) {
		cout << 0 << '\n';
		return 0;
	}
	int g = 0;

	for (int i = 0; i != 99999999; i++) {
		for (int j = 0; j != 9999999 - i; j++) {
			r = a[i] * a[j];
			if (g < r) {
				g = r;
			}
		}
	}
	cout << g << '\n';

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:52:2: error: expected '}' at end of input
   52 | }
      |  ^
a.cc:5:12: note: to match this '{'
    5 | int main() {
      |            ^