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

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

int main(void){
	cin.tie(0);
	ios::sync_with_stdio(false);
	string s;
	cin >> s;
	int left = 0;
	int right = s.size()-1;
	ll ans = 0;
	while(left!=right){
		if(s[left]==s[right]){
			left++;
			right--;
		}else if(s[left]=='x'){
			left++;
			ans++;
		}else if(s[right]=='x'){
			right--;
			ans++;
		}else{
			cout << -1 << endl;
			return 0;
		}
	}
	cout << ans << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:11:9: error: 'll' was not declared in this scope
   11 |         ll ans = 0;
      |         ^~
a.cc:18:25: error: 'ans' was not declared in this scope; did you mean 'abs'?
   18 |                         ans++;
      |                         ^~~
      |                         abs
a.cc:21:25: error: 'ans' was not declared in this scope; did you mean 'abs'?
   21 |                         ans++;
      |                         ^~~
      |                         abs
a.cc:27:17: error: 'ans' was not declared in this scope; did you mean 'abs'?
   27 |         cout << ans << endl;
      |                 ^~~
      |                 abs
Language: C++

#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
#include<utility>
#include<map>
#include<set>
#include<queue>
#include<math.h>
using namespace std;
#define N (1000000000+7)
#define INF 1e9
typedef long long ll;
typedef pair<ll,ll> P;
unsigned long long popCount64bitB(unsigned long long x) 
{ 
    x = ((x & 0xaaaaaaaaaaaaaaaaUL) >> 1) 
      +  (x & 0x5555555555555555UL); 
    x = ((x & 0xccccccccccccccccUL) >> 2) 
      +  (x & 0x3333333333333333UL); 
    x = ((x & 0xf0f0f0f0f0f0f0f0UL) >> 4) 
      +  (x & 0x0f0f0f0f0f0f0f0fUL); 
    x = ((x & 0xff00ff00ff00ff00UL) >> 8) 
      +  (x & 0x00ff00ff00ff00ffUL); 
    x = ((x & 0xffff0000ffff0000UL) >> 16) 
      +  (x & 0x0000ffff0000ffffUL); 
    x = ((x & 0xffffffff00000000UL) >> 32) 
      +  (x & 0x00000000ffffffffUL); 
    return x; 
} 


int main(void){
    string s;
    cin>>s;
    int ans=0;
    int l=0;r=s.length()-1;
    while(l<r){
        if(s[l]==s[r]){
            l++;
            r--;
        }
        else{
            if(s[l]=='x'){
                l--;
                ans++;
            }
            else{
                if(s[r]=='x'){
                    r--;
                    ans++;
                }
                else{
                    cout<<-1<<endl;
                    return 0;
                }
            }
        }
    }
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:37:13: error: 'r' was not declared in this scope
   37 |     int l=0;r=s.length()-1;
      |             ^
Language: C++

#include<iostream>
#include<string>

using namespace std;

int main(void) {

    string s;
    cin >> s;

    int ans = 0;

        // solve by dual poiters
        int f = 0;
        int b = s.size() - 1;

        while (l < r) {

            if (s[f] == s[b]) {
                f++;
                b--;                
            } else {
                if (s[f] == 'x') {
                    f++;
                    ans++;
                } else if(s[b] == 'x') {
                    b--;
                    ans++;
                } else {
                    cout << -1 << endl;
                    return 0;
                }
            }
        }

    cout << ans << endl;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:17:16: error: 'l' was not declared in this scope
   17 |         while (l < r) {
      |                ^
a.cc:17:20: error: 'r' was not declared in this scope
   17 |         while (l < r) {
      |                    ^
Language: C++

#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<map>
#include<set>
#include<cstdio>
#include<cmath>
#include<numeric>
#include<queue>
#include<stack>
#include<cstring>
#include<limits>
#include<functional>
#define rep(i,a) for(int i=(int)0;i<(int)a;++i)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define fi first
#define se second
using ll=long long;
static const ll mod = 1e9 + 7;
static const ll INF = 1LL << 50;
using namespace std;

int main(){
    string s;
    cin>>s;
    string t="";
    rep(i,s.size()){
        if(s[i]!='x')t+=string{s[i]};
        //xしか挿入出来ないのでそもそもxを除いた文字列が回文でなければならない
    }
    rep(i,t.size()/2){
        if(t[i]!=t[t.size()-1-i]){
            cout<<-1<<endl;
            return 0;
        }
    }
    vector<int>pre(t.size(),0),post(t.size(),0);
    int j=0,i=0;
    while(j<=t.size()/2){
        if(i>=n)break;
        if(s[i]!='x')++j;
        else pre[j]++;
        ++i;
    }j=0,i=s.size()-1;
    while(j<=t.size()/2){
        if(i<0)break;
        if(s[i]!='x')++j;
        else post[j]++;
        --i;
    }
    int ans=0;
    rep(i,j+1)ans+=abs(pre[i]-post[i]);
    cout<<ans<<endl;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:43:15: error: 'n' was not declared in this scope
   43 |         if(i>=n)break;
      |               ^
Language: C++

#include <iostream>
#include <string>
#include <iterator>
#include <algorithm>

template <class T>
T abs(T a) { return (a > 0 ? a : -a); };

int main() {
    std::string s, c;
    std::cin >> s;

    std::copy_if(s.begin(), s.end(), std::inserter(c, c.begin()), [](auto ch) { return ch != 'x'; });
    auto n = (int)c.length();
    for (auto i = 0; i < n; i++) {
        if (c[i] != c[n - 1 - i]) {
            std::cout << -1 << std::endl;
            return 0;
        }
    }

    auto index = 0;
    std::vector<int> v(n);
    for (auto i = 0; i < n; i++) {
        while (s[index] != c[i]) index++;
        v[i] = index;
    }

    auto ret = abs(v[0] - ((int)s.length() - v[n - 1] - 1)) * 2;
    for (auto i = 1; i < n; i++) {
        ret += abs((v[i] - v[i - 1]) - (v[n - i] - v[n - i - 1]));
    }

    std::cout << ret / 2 << std::endl;

    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:23:10: error: 'vector' is not a member of 'std'
   23 |     std::vector<int> v(n);
      |          ^~~~~~
a.cc:5:1: note: 'std::vector' is defined in header '<vector>'; this is probably fixable by adding '#include <vector>'
    4 | #include <algorithm>
  +++ |+#include <vector>
    5 | 
a.cc:23:17: error: expected primary-expression before 'int'
   23 |     std::vector<int> v(n);
      |                 ^~~
a.cc:26:9: error: 'v' was not declared in this scope
   26 |         v[i] = index;
      |         ^
a.cc:29:20: error: 'v' was not declared in this scope
   29 |     auto ret = abs(v[0] - ((int)s.length() - v[n - 1] - 1)) * 2;
      |                    ^
Language: C++

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

int main(int argc, char** argv)
{
	string S;
	std::vector<int> A;
	int ret = scanf("%s", &S);
	if(ret < 0)
		return -1;
	int N = S.length();
	int sta = 0;
	int end = N-1;
	int count = 0;
	while(sta<end)
	{
		if(S[start] == S[end])
		{
			sta++;
			end--;
		}
		else if(S[start] == 'x')
		{
			count++;
			start++;
		}
		else if(S[end] == 'x')
		{
			count++;
			end--;
		}
		else
		{
			count = -1;
			break;
		}
	}
	printf('%d\n', count);
	
	return 0;
}

Compiler output:
a.cc:42:16: warning: multi-character character constant [-Wmultichar]
   42 |         printf('%d\n', count);
      |                ^~~~~~
a.cc: In function 'int main(int, char**)':
a.cc:10:9: error: 'string' was not declared in this scope
   10 |         string S;
      |         ^~~~~~
a.cc:10:9: note: suggested alternatives:
In file included from /usr/include/c++/14/iosfwd:41,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:2:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
In file included from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:12:32: error: 'S' was not declared in this scope
   12 |         int ret = scanf("%s", &S);
      |                                ^
a.cc:21:22: error: 'start' was not declared in this scope; did you mean 'sta'?
   21 |                 if(S[start] == S[end])
      |                      ^~~~~
      |                      sta
a.cc:42:16: error: invalid conversion from 'int' to 'const char*' [-fpermissive]
   42 |         printf('%d\n', count);
      |                ^~~~~~
      |                |
      |                int
In file included from a.cc:1:
/usr/include/stdio.h:363:43: note:   initializing argument 1 of 'int printf(const char*, ...)'
  363 | extern int printf (const char *__restrict __format, ...);
      |                    ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~
Language: C++

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
#define MOD 1000000007

int main(){
  string s;
  cin>>s;
  int ind=s.length()-1,count=0;
  while(1){
    //cout<<s[i]<<" "<<s[ind]<<endl;
    if(i==ind) break;
    if(s[i]=='x'&&s[ind]=='x') ind--;
    else if(s[i]=='x'){
      count++;
    }else if(s[ind]=='x'){
      count++;
      i--;
      ind--;
    }else if(s[i]!=s[ind]){
      cout<<-1<<endl;
      return 0;
    }else{
      ind--;
    }
  }
  cout<<count<<endl;
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:13:8: error: 'i' was not declared in this scope
   13 |     if(i==ind) break;
      |        ^
a.cc:14:10: error: 'i' was not declared in this scope
   14 |     if(s[i]=='x'&&s[ind]=='x') ind--;
      |          ^
Language: C++

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
#define MOD 1000000007

int main(){
  string s;
  cin>>s;
  int ind=s.length()-1,count=0;
  wheile(1){
    //cout<<s[i]<<" "<<s[ind]<<endl;
    if(i==ind) break;
    if(s[i]=='x'&&s[ind]=='x') ind--;
    else if(s[i]=='x'){
      count++;
    }else if(s[ind]=='x'){
      count++;
      i--;
      ind--;
    }else if(s[i]!=s[ind]){
      cout<<-1<<endl;
      return 0;
    }else{
      ind--;
    }
  }
  cout<<count<<endl;
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:11:3: error: 'wheile' was not declared in this scope
   11 |   wheile(1){
      |   ^~~~~~
Language: C++

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
using namespace std;
char a[100000+5];
int head=0,tail,len,ans=0;

int main()
{
	ios::sync_with_stdio(false);
	gets(a);
	len=strlen(a);
	tail=len-1;
	while(tail!=head)
	{
		if(a[head]!=a[tail]&&a[head]!='x'&&a[tail]!='x') 
		{
			cout<<-1<<endl;
			return 0;
		}
		if(a[head]==a[tail]){head++;tail--;}
		if(a[head]!=a[tail]&&a[head]=='x')
		{
			ans++;
			head++;
		}
		if(a[head]!=a[tail]&&a[tail]=='x')
		{
			ans++;
			tail--;			
		}		
	}
	cout<<ans<<endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:13:9: error: 'gets' was not declared in this scope; did you mean 'getw'?
   13 |         gets(a);
      |         ^~~~
      |         getw
Language: C++

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
#include<queue>
using namespace std;
char a[100003];
int main()
{
	gets(a);
	int l=0,r=strlen(a)-1,pd=1,ans=0;
	while(l<r)
	{
		if(a[l]==a[r])
		{
			l++;
			r--;
		}
		if(a[l]!=a[r])
		{
			if(a[l]=='x'||a[r]=='x')
			{
				if(a[l]=='x')l++;
				if(a[r]=='x')r--;
				ans++;
			}
			else 
			{
				ans=-1;
				break;
			}
		}
	}
	cout<<ans;
	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:11:9: error: 'gets' was not declared in this scope; did you mean 'getw'?
   11 |         gets(a);
      |         ^~~~
      |         getw
Language: C++

#include <stdio.h>
#include <string>
#include <vector>
#include <algorithm>
#include <math.h>

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define FOR(i, n) for (int i = 0; i < int(n); i++)
#define FOR1(i, m, n) for (int i = int(m); i < int(n); i++)
#define MAX(a, b) ((a) >= (b) ? (a) : (b))
#define MIN(a, b) ((a) <= (b) ? (a) : (b))

int main(int argc, char *argv[argc])
{
  string str;
  vector<int> vec(1);
  char c;
  int index = 0;

  while(scanf("%c", &c)) {
    if (c == '\n') break;

    if (c == 'x') vec[index]++;
    else {
      str.push_back(c);
      vec.push_back(0);
      index++;
    }
  }

  string rstr = str;
  reverse(rstr.begin(), rstr.end());
  if (str != rstr) printf("-1\n");
  else {
    int front = 0;
    int back = vec.size() - 1;
    int ans = 0;
    while (front < back) {
      ans += abs(vec[front] - vec[back]);
      front++;
      back--;
    }
    printf("%d\n", ans);
  }
  
  return 0;
}


Compiler output:
a.cc:15:26: error: expected ',' or '...' before 'argv'
   15 | int main(int argc, char *argv[argc])
      |                          ^~~~
a.cc:15:5: warning: second argument of 'int main(int, char*)' should be 'char **' [-Wmain]
   15 | int main(int argc, char *argv[argc])
      |     ^~~~
Language: C++

#include<iostream>
#include<cstdio>
#include<string>
using namespace std;
 
int main() {
  string s;
  cin >> s;
  int n = s.length();
  string w = "";
  for (int i = 0; i < (int) s.length(); i++) {
    if (s[i] != 'x') {
      w += s[i];
    }
  }
  string ww = w;
  reverse(ww.begin(), ww.end());
  if (w != ww) {
    printf("%d\n", -1);
    return 0;
  }
  int ans = 0;
  int i = 0, j = n - 1;
  while (i < j) {
    if (s[i] == s[j]) {
      i++;
      j--;
      continue;
    }
    ans++;
    if (s[i] == 'x') {
      i++;
    } else {
      j--;
    }
  }
  printf("%d\n", ans);
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:17:3: error: 'reverse' was not declared in this scope
   17 |   reverse(ww.begin(), ww.end());
      |   ^~~~~~~
Language: C++

#include <iostream>
using namespace std;

int main() {
	int f, b , cnt = 0;
	string s;
	cin >> s;
	f = 0, b = s.size() - 1;
	while(l<=b){
	  if(s[f] == s[b]){//端が一致で無視.
	  	f++;
	  	b--;
	  }
	  else if((s[f] != 'x') && (s[b] != 'x')){
	  	cout << -1 << endl;
	  	return 0;
	  }
	  else if(s[f] == 'x'){
	  	cnt++;
	  	f++;
	  }
	  else{//s[b] == 'x'
	  	cnt++;
	  	r--;
	  }
	}
	cout << cnt << endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:15: error: 'l' was not declared in this scope
    9 |         while(l<=b){
      |               ^
a.cc:24:17: error: 'r' was not declared in this scope
   24 |                 r--;
      |                 ^
Language: C++

#include <string>

#include <iostream>

using namespace std;

int main(){
	int c;
	string s;

	cin >> s;

	int left=0, right;
	right=(int)s.size() - 1;

	int h=(int)s.size() / 2;

	for(int i=0; i<h;i++){
		if(s[left] == s[right]){
			left++;
			right--;
		}else if(s[left] == 'x'){
			left++;
			c++;
		}else if(s[right] == 'x'){
			right--;
			c++;
		}else{
			cout << -1 << endl;
			return 0;
	}

	cout << c << endl;

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:36:2: error: expected '}' at end of input
   36 | }
      |  ^
a.cc:7:11: note: to match this '{'
    7 | int main(){
      |           ^
Language: C++

#include<cstdio>
#include<iostream>
#include<cstring>
#include<string>
#include<cmath>
#include<algorithm>
#include<queue>
#include<cstdlib>

using namespace std;

const int MAXN=100010;
char s[MAXN];

int main()
{
	scanf("%s",s);
	int len=strlen(s);
	int ans=0;
	int start=0,end=len-1;
	while (start<end)
	{
		if (s[start]==s[end])
		{
			start++;
			end++;
		}
		else if (s[start]=='x')
		{
			ans++;
			l++;
		}
		else if (s[end]=='x')
		{
			ans++;
			r--;
		}
		else 
		{
			cout<<-1;
			return 0;
		}
	}
	cout<<ans;
	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:31:25: error: 'l' was not declared in this scope
   31 |                         l++;
      |                         ^
a.cc:36:25: error: 'r' was not declared in this scope
   36 |                         r--;
      |                         ^
Language: C++

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

using namespace std;

int Abs(int x){
	if (x < 0)
		return -x;
	else
		return x;
}

int main(void){
	
	char *c = (char *)malloc(50001*sizeof(char));

	vector< vector<int> > alp(26, vector<int>(0));
	cin >> c;

	int i = 0;
	while (scanf("%c", &c[i]) != EOF){
		;
	}

	for (int i = 0; i < c.size(); i++){
		alp[c[i]-'a'].push_back(i);
	}

	for (int i = 0; i < 26; i++){
		for (int j = 0; j < 26; j++){
			if (j != 23 && i != 23){
				int num = 0;
				for (auto itr1 = alp[j].begin(); itr1 < alp[j].end(); itr1++){
					for (auto itr2 = alp[i].begin(); itr2 < alp[i].end(); itr2++){
						if (*itr1 < *itr2){
							num++;
						}
						else if (*itr1 > *itr2)
							num--;
					}
				}
				if (num != 0){
					cout << -1 << endl;
					return 0;
				}	
			}
		}
	}


	int num = 0;
	int sum = 0;
	for (int i = 0; i < 26; i++){
		if (i != 23) {
			for (auto itr1 = alp[i].begin(); itr1 < alp[i].end(); itr1++){
				for (auto itr = alp[23].begin(); itr < alp[23].end(); itr++){
					if (*itr1 < *itr)
						num++;
					else if (*itr1 > *itr)
						num--;
				}
				if (num != 0){
					sum = i;
					break;
				}
			}
		}
	}

	if (num < 0)
		num = -num;
//	cout << num << " " << alp[sum].size() << endl;
	cout << (num / (int)alp[sum].size()) << endl;

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:29:31: error: request for member 'size' in 'c', which is of non-class type 'char*'
   29 |         for (int i = 0; i < c.size(); i++){
      |                               ^~~~
Language: C++

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

using namespace std;

int Abs(int x){
	if (x < 0)
		return -x;
	else
		return x;
}

int main(void){
	
	char *c = malloc(50001*sizeof(char));

	vector< vector<int> > alp(26, vector<int>(0));
	cin >> c;

	for (int i = 0; i < strlen(c); i++){
		alp[c[i]-'a'].push_back(i);
	}

	for (int i = 0; i < 26; i++){
		for (int j = 0; j < 26; j++){
			if (j != 23 && i != 23){
				int num = 0;
				for (auto itr1 = alp[j].begin(); itr1 < alp[j].end(); itr1++){
					for (auto itr2 = alp[i].begin(); itr2 < alp[i].end(); itr2++){
						if (*itr1 < *itr2){
							num++;
						}
						else if (*itr1 > *itr2)
							num--;
					}
				}
				if (num != 0){
					cout << -1 << endl;
					return 0;
				}	
			}
		}
	}


	int num = 0;
	int sum = 0;
	for (int i = 0; i < 26; i++){
		if (i != 23) {
			for (auto itr1 = alp[i].begin(); itr1 < alp[i].end(); itr1++){
				for (auto itr = alp[23].begin(); itr < alp[23].end(); itr++){
					if (*itr1 < *itr)
						num++;
					else if (*itr1 > *itr)
						num--;
				}
				if (num != 0){
					sum = i;
					break;
				}
			}
		}
	}

	if (num < 0)
		num = -num;

	cout << (num / (int)alp[sum].size()) << endl;

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:18:25: error: invalid conversion from 'void*' to 'char*' [-fpermissive]
   18 |         char *c = malloc(50001*sizeof(char));
      |                   ~~~~~~^~~~~~~~~~~~~~~~~~~~
      |                         |
      |                         void*
Language: C++

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

using namespace std;

int Abs(int x){
	if (x < 0)
		return -x;
	else
		return x;
}

int main(void){
	
	char *c = calloc(50001, sizeof(char));

	vector< vector<int> > alp(26, vector<int>(0));
	cin >> c;

	for (int i = 0; i < strlen(c); i++){
		alp[c[i]-'a'].push_back(i);
	}

	for (int i = 0; i < 26; i++){
		for (int j = 0; j < 26; j++){
			if (j != 23 && i != 23){
				int num = 0;
				for (auto itr1 = alp[j].begin(); itr1 < alp[j].end(); itr1++){
					for (auto itr2 = alp[i].begin(); itr2 < alp[i].end(); itr2++){
						if (*itr1 < *itr2){
							num++;
						}
						else if (*itr1 > *itr2)
							num--;
					}
				}
				if (num != 0){
					cout << -1 << endl;
					return 0;
				}	
			}
		}
	}


	int num = 0;
	int sum = 0;
	for (int i = 0; i < 26; i++){
		if (i != 23) {
			for (auto itr1 = alp[i].begin(); itr1 < alp[i].end(); itr1++){
				for (auto itr = alp[23].begin(); itr < alp[23].end(); itr++){
					if (*itr1 < *itr)
						num++;
					else if (*itr1 > *itr)
						num--;
				}
				if (num != 0){
					sum = i;
					break;
				}
			}
		}
	}

	if (num < 0)
		num = -num;

	cout << (num / (int)alp[sum].size()) << endl;

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:17:25: error: invalid conversion from 'void*' to 'char*' [-fpermissive]
   17 |         char *c = calloc(50001, sizeof(char));
      |                   ~~~~~~^~~~~~~~~~~~~~~~~~~~~
      |                         |
      |                         void*
Language: Java

import java.util.Scanner;
import java.util.Stack;
 
class Main {
 
    public static void main(String[] args) {
        new Main().compute();
    }
 
    void compute() {
        Scanner sc = new Scanner(System.in);
        String S = sc.next();
        List<Character> removedX = new ArrayList<>();
        boolean[] isX = new boolean[S.length()];
        for (int i = 0; i < S.length(); i++) {
            if (S.charAt(i) == 'x') {
                isX[i] = true;
            } else {
               removedX.add(S.charAt(i));
            }
        }
        for (int i = 0; i < removedX.size() / 2; i++) {
            if (removedX.get(i) != removedX.get(removedX.size() - i - 1)) {
                System.out.println(-1);
                return;
            }
        }
        int ans = 0;
        int head = 0;
        int foot = S.length() - 1;
        while (foot - head > 0) {
            if (isX[head] == isX[foot]) {
                head++;
                foot--;
            } else if (isX[head] && !isX[foot]) {
                head++;
                ans++;
            } else {
                foot--;
                ans++;
            }
        }
        System.out.println(ans);
    }
}

Compiler output:
Main.java:13: error: cannot find symbol
        List<Character> removedX = new ArrayList<>();
        ^
  symbol:   class List
  location: class Main
Main.java:13: error: cannot find symbol
        List<Character> removedX = new ArrayList<>();
                                       ^
  symbol:   class ArrayList
  location: class Main
2 errors
Language: Java

import java.util.Scanner;
import java.util.Stack;
 
class Main {
 
    public static void main(String[] args) {
        new Main().compute();
    }
 
    void compute() {
        Scanner sc = new Scanner(System.in);
        String S = sc.next();
        List<Character> removedX = new ArrayList<>();
        boolean[] isX = new boolean[S.length()];
        for (int i = 0; i < S.length(); i++) {
            if (S.charAt(i) == 'x') {
                isX[i] = true;
            } else {
               removedX.add(S.charAt(i));
            }
        }
        for (int i = 0; i < removedX.size() / 2; i++) {
            if (removedX.get(i) != removedX.get(removedX.size() - i - 1)) {
                System.out.println(-1);
                return;
            }
        }
        int ans = 0;
        int head = 0;
        int foot = S.length() - 1;
        while (foot - head > 0) {
            if (isX[head] == isX[foot]) {
                head++;
                foot--;
            } else if (isX[head] && !isX[foot]) {
                head++;
                ans++;
            } else {
                foot--;
                ans++;
            }
        }
        System.out.println(-1);
    }
}

Compiler output:
Main.java:13: error: cannot find symbol
        List<Character> removedX = new ArrayList<>();
        ^
  symbol:   class List
  location: class Main
Main.java:13: error: cannot find symbol
        List<Character> removedX = new ArrayList<>();
                                       ^
  symbol:   class ArrayList
  location: class Main
2 errors
Language: Java

import java.util.Scanner;

public class MainC {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		int n = s.length();
		int ans = 0, l = 0, r = n - 1;
		if(n == 1) {
			System.out.println(0);
			return;
		}
		for(; ; ) {
			if(s.charAt(l) == s.charAt(r)) {
				l++; r--;
				if(l == r) {
					System.out.println(ans);
					return;
				}
			} else {
				if(s.charAt(l) != 'x' && s.charAt(r) != 'x') {
					System.out.println(-1);
					return;
				} else {
					if(s.charAt(l) == 'x') {
						l++;
						ans++;
						if(l == r) {
							System.out.println(ans);
							return;
						}
					}
					if(s.charAt(r) == 'x') {
						r--;
						ans++;
						if(l == r) {
							System.out.println(ans);
							return;
						}
					}
				}
			}
		}
	}
}


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

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

int main()
{
    string s;
    cin >> s;


    long long int len = s.length();
    if( len == 1 ){
        cout << 0 << endl;
        return 0;
    }


    long long int ans = 0;
    for( int i = 0, j = len-1; i < j; ++i, --j ){
        if( s[i] == s[j] ) continue;
	else if( s[i] != 'x' &&	s[j] !=	'x' ){ cout << -1 << endl; return 0; }
        else {
            ++ans;
            j += (s[i] == 'x');
            i -= (s[j] == 'x');
 	}


    cout << ans << endl;

    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:32:2: error: expected '}' at end of input
   32 | }
      |  ^
a.cc:6:1: note: to match this '{'
    6 | {
      | ^
Language: C++

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

int main()
{
    string s;
    cin >> s;


    long long int len = s.length();
    if( len == 1 ){
        cout << 0 << endl;
        return 0;
    }


    long long int ans = 0;
    for( int i = 0, j = len-1; i < j; ++i, --j ){
        if( s[i] == s[j] ) continue;
	else if( s[i] != 'x' &&	s[j] !=	'x' ){ cout << -1 << endl return 0; }
        else {
            ++ans;
            j += (s[i] == 'x');
            i -= (s[j] == 'x');
 	}


    cout << ans << endl;

    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:21:66: error: expected ';' before 'return'
   21 |         else if( s[i] != 'x' && s[j] != 'x' ){ cout << -1 << endl return 0; }
      |                                                                  ^~~~~~~
      |                                                                  ;
a.cc:32:2: error: expected '}' at end of input
   32 | }
      |  ^
a.cc:6:1: note: to match this '{'
    6 | {
      | ^
Language: C++

#include<math.h>
#include<limits.h>
#include<iostream>
#include<string>
#include<vector>
#include<stdio.h>
#include<sstream>
#include<list>
#include<queue>
#include <algorithm>
#include<initializer_list>
#include<map>
#include<set>
using namespace std;
bool kaibun(string s) {
	int n = s.length();
	for (int i = 0; i < (int)s.length()/2+1; i++) {
		if (s[i] != s[n - 1 - i])return false;
	}
	return true;
}
int main() {
	string s;
	cin >> s;
	string rmx = s;
	int xnum = 0;
	for (auto it = rmx.begin(); it != rmx.end();) {

		if (*it == 'x') {
			it = rmx.erase(it);
			xnum++;
		}
		else it++;
	}
	bool kai = kaibun(rmx);

	int count = 0;
	if (kai) {
		int pi = (int)ceil(rmx.length() / 2.0);
		list<char> st(0);
		int i = 0;
		int j = 0;
		while (true) {

			st.push_back(s[i]);
			i++;
			if (s[i] == rmx[j]) j++;
			if (i == (int)ceil(s.length() / 2.0)) {
				break;
			}
		}
		i = 0;
		int pivot = (int)ceil(s.length() / 2.0);
		while (!st.empty()) {
			char a = st.back();
			st.pop_back();
			if (a != s[pivot + i])count++;
			i++;
		}
		count += s.length - i;
	}
	else {
		cout << "-1";
		return 0;
	}
	cout << count;
	return 0;
}





Compiler output:
a.cc: In function 'int main()':
a.cc:60:28: error: invalid use of member function 'std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::length() const [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>; size_type = long unsigned int]' (did you forget the '()' ?)
   60 |                 count += s.length - i;
      |                          ~~^~~~~~
      |                                  ()
Language: C++

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

string s;

int main() {
    cin >> s;
    int res = 0;
    int i = 0, j = s.length() - 1;
    if (s.length() == 1) {
	cout << 0 << endl;
	return 0;
    }
    while (j > i && s.length() % 2 == 0) {
	if (s[i] == s[j]) {
	    if (i < s.length()) i++;
	    if (j != 0) j--;
	}
	else if (s[i] == 'x') {
	    res++;
	    if (i < s.length()) i++;
	}
	else if (s[j] == 'x') {
	    res++;
	    if (j != 0) j--;
	}
    }
    while (j >= i && s.length() % 2 == 1) {
	if (s[i] == s[j]) {
	    if (i < s.length() i++;
	    if (j != 0 j--;
	}
	else if (s[i] == 'x') {
	    res++;
	    if (i < s.length()) i++;
	}
	else if (s[j] == 'x') {
	    res++;
	    if (j != 0) j--;
	}
    }
    cout << res << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:31:31: error: expected ';' before 'i'
   31 |             if (i < s.length() i++;
      |                               ^~
      |                               ;
a.cc:32:13: error: expected primary-expression before 'if'
   32 |             if (j != 0 j--;
      |             ^~
a.cc:31:36: error: expected ')' before 'if'
   31 |             if (i < s.length() i++;
      |                ~                   ^
      |                                    )
   32 |             if (j != 0 j--;
      |             ~~
Language: C++

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

bool isKaibun(string str)
{
  int i = 0;
  while(i < str.length() - 1 - i)
  {
    if (str[i] != str[str.length() - 1 - i]) return false;
    ++i;
  }
  return true;
}

int main(){
  string s;
  cin >> s;
  bool result = true;
  int cont = 0;
  bool isX = true;
  for (int k = 0; k < s.length(); ++k)
  {
    if (s[k] != 'x') isX = false;
  }
  if(!isKaibun(s))
  {
    string ss;
    for (int j = 0; j < s.length(); ++j)
    {
      if (s[j] == 'x') ++cont;
      else ss.push_back(s[j]);
    }
    if(!isKaibun(ss)) result = false;
  }  
  if(isX) cout = 0;
  if(result) cout << cont << endl;
  else cout << -1 << endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:35:18: error: no match for 'operator=' (operand types are 'std::ostream' {aka 'std::basic_ostream<char>'} and 'int')
   35 |   if(isX) cout = 0;
      |                  ^
In file included from /usr/include/c++/14/istream:41,
                 from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127,
                 from a.cc:1:
/usr/include/c++/14/ostream:458:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator=(std::basic_ostream<_CharT, _Traits>&&) [with _CharT = char; _Traits = std::char_traits<char>]'
  458 |       operator=(basic_ostream&& __rhs)
      |       ^~~~~~~~
/usr/include/c++/14/ostream:458:33: note:   no known conversion for argument 1 from 'int' to 'std::basic_ostream<char>&&'
  458 |       operator=(basic_ostream&& __rhs)
      |                 ~~~~~~~~~~~~~~~~^~~~~
Language: C++

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

string s;

int main() {
    cin >> s;
    int res = 0;
    int i = 0, j = s.length() - 1;
    while (j > i && s.length() % 2 == 0) {
	if (s[i] == s[j]) {
	    i++; j--;
	}
	else if (s[i] == 'x') {
	    res++;
	    if (i < s.length()) i++;
	}
	else if (s[j] == 'x') {
	    res++;
	    if (j != 0) j--;
	}
    }
    while (j >= i && s.length() % 2 == 1) {
	if (s[i] == s[j]) {
	    i++; j--;
	}
	else if (s[i] == 'x') {
	    res++;
	    if (i < s.length() i++;
	}
	else if (s[j] == 'x') {
	    res++;
	    if (j != 0) j--;
	}
    }
    cout << res << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:30:31: error: expected ';' before 'i'
   30 |             if (i < s.length() i++;
      |                               ^~
      |                               ;
a.cc:31:9: error: expected primary-expression before '}' token
   31 |         }
      |         ^
a.cc:30:36: error: expected ')' before '}' token
   30 |             if (i < s.length() i++;
      |                ~                   ^
      |                                    )
   31 |         }
      |         ~                           
a.cc:31:9: error: expected primary-expression before '}' token
   31 |         }
      |         ^
Language: C++

#include <bits/stdc++.h>
using namespace std;
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)
#define CLR(mat) memset(mat, 0, sizeof(mat))
typedef long long ll;
int alph[26]={0};

bool check(int rl,string sc){
	int n;
	n = rl/2;
	for(int i=0;i<n;i++){
		if(sc[i]!=sc[rl-1-i])return false;
	}
	return true;
}
int tyuusin(string s,string sc,int rl,int l){
	char x;
	x = sc[rl/2];
	int k=0;
	for(int i=0;i<l;i++){
		if(s[i]==x)++k;
		if(k==alph[x-'a']){
			return i;
		}
	}
}


int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	int rl=0;
	string s,sc;
	int xiti[100000]={0};
	cin >> s;
	
	//check1
	int x=0,l;
	l = s.size();
	FOR(i,0,l){
		if(s[i]=='x'){
			++x;
			xiti[i]=1;
		}else{
			++alph[s[i]-'a'];
			++rl;
			sc+=s[i];
		}
	}
	if(sc.size()==0){
		cout << 0 << endl;
		return 0;
	}

	//check2
	bool ok = check(rl,sc);
	if(ok==true &&x==0){
		cout << 0 << endl;
		break;
	}

	if(ok){
		int t = tyuusin(s,sc,rl,l);
		int k = rl&1;
		if(k==1)k=0;
		else k=1;
		//cout << t << " " << k<<endl;
		int i=1;
		int j=1;
		int ans=0;
		while(1){
			if(t-i<0 || t+j+k>=l-1){
				if(t-i<0){
					ans+=((l-1)-(t+j+k));
				}else{
					ans+=t-i;
				}
				break;
			}
			if(s[t-i]=='x' && s[t+j+k]=='x'){
				i++;j++;
			}else if(s[t-i]!='x' && s[t+j+k]!='x'){
				i++;j++;
			}else if(s[t-i]!='x' && s[t+j+k]=='x'){
				j++;
				ans++;
			}else{
				i++;
				ans++;
			}
		}	
		cout << ans << endl;





	}else{
		cout << -1 << endl;
	}
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:59:17: error: break statement not within loop or switch
   59 |                 break;
      |                 ^~~~~
a.cc: In function 'int tyuusin(std::string, std::string, int, int)':
a.cc:26:1: warning: control reaches end of non-void function [-Wreturn-type]
   26 | }
      | ^
Language: C++

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

#define int_inf 1000000000
#define ll_inf	100000000000000000000000

using namespace std;


int main(){
	string s;
	cin >> s;
	
	multiset<char> se;
	for(int i=0; i<s.size(); i++) se.insert(s[i]);
	int a=0;
	char c;
	while(se.size()){
		if(count(se.begin())%2==0) se.erase(se.begin());
		else{
			a+=1;
			c=*(se.begin());
	}
	if(a>1){
		cout <<-1<<endl;
		return 0;
	}
	for(int i=0; i<s.size(), i++){
		if(s[i]==c){ a=i; break; }
	}
	
	string s2, s3, s4;
	s2 = s.substr(0, a);
	s3 = s.substr(a+1, s.size()-a);
	for(int i=0; i<s2.size(); i++){
		s4 += s2[s2.size()-1-i];
	}
	long long index=0;
	while(s3!=s4){
		if(s3[index]==s4[index]) index+=1;
		else if(s3[index]=='x') s4.insert(s4.begin()+index,'x');
		else if(s4[index]=='x') s3.insert(s3.begin()+index,'x');
		else{
			cout <<-1<<endl;
			return 0;
		}
	}
	
	cout << s3.size()+s4.size()+1-s.size() << endl;
	return 0;
}
	
	
		


Compiler output:
a.cc: In function 'int main()':
a.cc:22:25: error: no matching function for call to 'count(std::multiset<char>::iterator)'
   22 |                 if(count(se.begin())%2==0) se.erase(se.begin());
      |                    ~~~~~^~~~~~~~~~~~
In file included from /usr/include/c++/14/algorithm:61,
                 from a.cc:5:
/usr/include/c++/14/bits/stl_algo.h:4025:5: note: candidate: 'template<class _IIter, class _Tp> typename std::iterator_traits< <template-parameter-1-1> >::difference_type std::count(_IIter, _IIter, const _Tp&)'
 4025 |     count(_InputIterator __first, _InputIterator __last, const _Tp& __value)
      |     ^~~~~
/usr/include/c++/14/bits/stl_algo.h:4025:5: note:   candidate expects 3 arguments, 1 provided
In file included from /usr/include/c++/14/algorithm:86:
/usr/include/c++/14/pstl/glue_algorithm_defs.h:101:1: note: candidate: 'template<class _ExecutionPolicy, class _ForwardIterator, class _Tp> __pstl::__internal::__enable_if_execution_policy<_ExecutionPolicy, typename std::iterator_traits<_II>::difference_type> std::count(_ExecutionPolicy&&, _ForwardIterator, _ForwardIterator, const _Tp&)'
  101 | count(_ExecutionPolicy&& __exec, _ForwardIterator __first, _ForwardIterator __last, const _Tp& __value);
      | ^~~~~
/usr/include/c++/14/pstl/glue_algorithm_defs.h:101:1: note:   candidate expects 4 arguments, 1 provided
a.cc:31:37: error: expected ';' before ')' token
   31 |         for(int i=0; i<s.size(), i++){
      |                                     ^
      |                                     ;
a.cc:54:2: error: expected '}' at end of input
   54 | }
      |  ^
a.cc:13:11: note: to match this '{'
   13 | int main(){
      |           ^
Language: Java

import java.util.Scanner;
import java.util.Stack;

class Main {

    public static void main(String[] args) {
        new Main().compute();
    }

    void compute() {
        Scanner sc = new Scanner(System.in);
        String S = sc.next();
        List<Character> removedX = new ArrayList<>();
        int N = S.length();
        boolean[] isX = new boolean[N];
        for (int i = 0; i < N; i++) {
            if (S.charAt(i) == 'x') {
                isX[i] = true;
            } else {
               removedX.add(S.charAt(i));
            }
        }
        int rN = removedX.size();
        for (int i = 0; i < rN / 2; i++) {
            if (removedX.get(i) != removedX.get(rN - i - 1)) {
                System.out.println(-1);
                return;
            }
        }
        int ans = 0;
        int head = 0;
        int foot = N - 1;
        while (foot - head > 0) {
            if (isX[head] == isX[foot]) {
                head++;
                foot--;
            } else if (isX[head] && !isX[foot]) {
                head++;
                ans++;
            } else {
                foot--;
                ans++;
            }
        }
        System.out.println(ans);
    }
}


Compiler output:
Main.java:13: error: cannot find symbol
        List<Character> removedX = new ArrayList<>();
        ^
  symbol:   class List
  location: class Main
Main.java:13: error: cannot find symbol
        List<Character> removedX = new ArrayList<>();
                                       ^
  symbol:   class ArrayList
  location: class Main
2 errors
Language: C++

#include <bits/stdc++.h>
using namespace std;
#define MAX_N 100005

string str;
set<char> charset;
int r, l num = 0;
int diff[MAX_N];

bool dual() {
  r = 0; l = str.size() - 1;
  while (r < l) {
    if (str[r] != str[l]) return false;
  }
  return true;
}

int main(void){
  cin >> str;
  for (int i = 0; i < str.size(); ++i) {
    charset.insert(str[i]);
  }

  charset.erase('x');

  if (charset.size() >= 2 && !dual()) {
    printf("-1\n");
    return 0;
  }

  return 0;
}

Compiler output:
a.cc:7:10: error: expected initializer before 'num'
    7 | int r, l num = 0;
      |          ^~~
a.cc: In function 'bool dual()':
a.cc:11:10: error: 'l' was not declared in this scope
   11 |   r = 0; l = str.size() - 1;
      |          ^
Language: C++

#include <bits/stdc++.h>
using namespace std;
ios::sync_with_stdio(false);


int main()
{
    string s;
    cin >> s;
    int n = s.length();
    int c = 0;
    int k = n-1;
    int i = 0;
    while(i < (n+c)/2)
    {
        if(s[i] != s[k-i] && s[i] != 'x' && s[k-i] != 'x')
        {
            cout << -1 << endl;
            return 0;
        }
        else if(s[i] != s[k-i] && s[i] != 'x')
        {
            c = c + 1;
            k = k + 1;
            s.insert(i, "x");
            i = i + 1;
        }
        else if(s[i] != s[k-i])
        {
            c = c + 1;
            k = k + 1;
            if(i == 0)
            {
                s += "x";
            }
            else
            {
                s.insert(k-i+1, "x");
            }
            i = i + 1;
        }
        else
        {
            i = i + 1;
        }
        
    }
    cout << c << endl;
}

Compiler output:
a.cc:3:1: error: specializing member 'std::basic_ios<char>::sync_with_stdio' requires 'template<>' syntax
    3 | ios::sync_with_stdio(false);
      | ^~~
Language: C

#include <stdio.h>
#include <stdlib.h>
int main() {
	char s[100010], dex[100010];
	long long int ans = 0, len, l = 0, r = 0;
	scanf("%s", s);
	len = strlen(s);
	for (int i = 0; i + l == len - i + r; i++)
	{
		if (a[i + l] != a[len - i - r]) {
			if (a[i + l] == 'x') {
				i--;
				l++;
				ans++;
			}
			if (a[len - i + r] == 'x') {
				i--;
				r++;
				ans++;
			}
			if (a[i + l] == 'x' && a[len - i + r] == 'x') {
				printf("-1");
				return 0;
			}
		}
	}
	printf("%d", ans);
	return 0;
}

Compiler output:
main.c: In function 'main':
main.c:7:15: error: implicit declaration of function 'strlen' [-Wimplicit-function-declaration]
    7 |         len = strlen(s);
      |               ^~~~~~
main.c:3:1: note: include '<string.h>' or provide a declaration of 'strlen'
    2 | #include <stdlib.h>
  +++ |+#include <string.h>
    3 | int main() {
main.c:7:15: warning: incompatible implicit declaration of built-in function 'strlen' [-Wbuiltin-declaration-mismatch]
    7 |         len = strlen(s);
      |               ^~~~~~
main.c:7:15: note: include '<string.h>' or provide a declaration of 'strlen'
main.c:10:21: error: 'a' undeclared (first use in this function)
   10 |                 if (a[i + l] != a[len - i - r]) {
      |                     ^
main.c:10:21: note: each undeclared identifier is reported only once for each function it appears in
Language: C++

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

int main(){
    string s;
    cin >> s;
    long long int i = 0, j, ans = 0;
    j = s.length() - 1;
    while(true){
        if(i => j){
            break;
        }
        if(s[i] == s[j]){
            i++;
            j--;
        }
        else{
            if(s[i] == 'x'){
                ans++;
                i++;
            }
            else if(s[j] == 'x'){
                ans++;
                j--;
            }
            else{
                cout << -1 << endl;
                return 0;
            }
        }
    }
    cout << ans << endl;
    return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:13:15: error: expected primary-expression before '>' token
   13 |         if(i => j){
      |               ^
Language: C++

#include <math.h>
#include <vector>
using namespace std;

int main(){
    string s;
    cin >> s;
    long long int i = 0, j, ans = 0;
    j = s.length() - 1;
    while(true){
        if(i => j){
            break;
        }
        if(s[i] == s[j]){
            i++;
            j--;
        }
        else{
            if(s[i] == 'x'){
                ans++;
                i++;
            }
            else if(s[j] == 'x'){
                ans++;
                j--;
            }
            else{
                cout << -1 << endl;
                return 0;
            }
        }
    }
    cout << ans << endl;
    return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:6:5: error: 'string' was not declared in this scope
    6 |     string s;
      |     ^~~~~~
a.cc:3:1: note: 'std::string' is defined in header '<string>'; this is probably fixable by adding '#include <string>'
    2 | #include <vector>
  +++ |+#include <string>
    3 | using namespace std;
a.cc:7:5: error: 'cin' was not declared in this scope
    7 |     cin >> s;
      |     ^~~
a.cc:3:1: note: 'std::cin' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
    2 | #include <vector>
  +++ |+#include <iostream>
    3 | using namespace std;
a.cc:7:12: error: 's' was not declared in this scope
    7 |     cin >> s;
      |            ^
a.cc:11:15: error: expected primary-expression before '>' token
   11 |         if(i => j){
      |               ^
a.cc:28:17: error: 'cout' was not declared in this scope
   28 |                 cout << -1 << endl;
      |                 ^~~~
a.cc:28:17: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:28:31: error: 'endl' was not declared in this scope
   28 |                 cout << -1 << endl;
      |                               ^~~~
a.cc:3:1: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
    2 | #include <vector>
  +++ |+#include <ostream>
    3 | using namespace std;
a.cc:33:5: error: 'cout' was not declared in this scope
   33 |     cout << ans << endl;
      |     ^~~~
a.cc:33:5: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:33:20: error: 'endl' was not declared in this scope
   33 |     cout << ans << endl;
      |                    ^~~~
a.cc:33:20: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
Language: Java

import java.util.Scanner;  
public class Main{  
    public static void main(String[] args){  
        Scanner scanner = new Scanner(System.in);  
        int f = scanner.nextInt();  
        scanner = new Scanner(System.in);  
        String str = new String;  
            str = scanner.nextLine();  
            System.out.println(str.length()-longest(str));  
    }  
    public static int longest(String str){  
        String rts = "";  
        int length = str.length();  
        int[][] ints = new int[length][length];  
        for(int i=length;i>0;i--){  
            rts+=str.substring(i-1,i);  
        }  
        for(int x=0;x<length;x++){  
            for(int y=0;y<length;y++){  
                String char1=str.substring(x,x+1);  
                String char2=rts.substring(y,y+1);  
                if (char1.equals(char2)){  
                    if(x!=0&y!=0){  
                        ints[x][y]=ints[x-1][y-1]+1;  
                    }else{  
                        ints[x][y]=1;  
                    }  
                }else{  
                    if(x==0&y==0){  
                        ints[x][y]=0;  
                    }else if(x == 0&y!=0){  
                        ints[x][y]=ints[x][y-1];  
                    }else if(y==0&x!=0){  
                        ints[x][y]=ints[x-1][y];  
                    }else{  
                        if(ints[x-1][y]>ints[x][y-1]){  
                            ints[x][y]=ints[x-1][y];  
                        }else{  
                            ints[x][y]=ints[x][y-1];  
                        }  
                    }  
                }  
            }  
        }  
        return ints[length-1][length-1];  
    }  
}

Compiler output:
Main.java:7: error: '(' or '[' expected
        String str = new String;  
                               ^
1 error
Language: C++

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

#define debug(x) cerr<<#x<<'='<<x<<'\n'

const int N=1e5+6;
int n;
char y[N], c[N];
int ly, lc;

int main(void) {
	scanf("%s", y+1);
	int i=1, j=strlen(y+1);
	int ans=0;
	while (i<=j) {
		if (y[i]==y[j]) {
			i++;
			j--;
			continue;
		}a
		if (y[i]=='x') {
			ans++;
			i++;
			continue;
		}
		if (y[j]=='x') {
			ans++;
			j--;
			continue;
		}
		puts("-1");
		return 0;
	}
	cout<<ans;	
	return 0;
}
	

Compiler output:
a.cc: In function 'int main()':
a.cc:23:18: error: 'a' was not declared in this scope
   23 |                 }a
      |                  ^