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

#include <bits/stdc++.h>
//#include <boost/multiprecision/cpp_int.hpp>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#pragma GCC optimize("O3")
#define REP(i,n) for(int i=0;i<n;i++)
#define REPP(i,n) for(int i=1;i<=n;i++)
#define ALL(obj) (obj).begin(), (obj).end()
#define EPS (1e-9)
#define INF (1e17)
#define PI (acos(-1))
//const double PI = acos(-1);
//const double EPS = 1e-15;
//long long INF=(long long)1E17;
#define i_7 (long long)(1e9+7)
//#define i_7 998'244'353
long mod(long a){
    long long c=a%i_7;
    if(c>=0)return c;
    return c+i_7;
}
long long po(long a, long b){
    if(b==0){
        return 1;
    }
    
    long long z = po(a,b/2);
    z = mod(z*z);
    if(b%2!=0){
        z = mod(a*z);
    }
    return z;
}
 
bool prime_(int n){
  if(n==1){
    return false;
  }else if(n==2){
    return true;
  }else{
    for(int i=2;i<=std::sqrt(n);i++){
      if(n%i==0){
        return false;
      }
    }
    return true;
  }
}
 
long long gcd_(long long a, long long b){
  if(a<b){
    std::swap(a,b);
  }
  if(a%b==0){
    return b;
  }else{
    return gcd_(b,a%b);
  }
}
 
long long lcm_(long long x, long long y){
  return (x/gcd_(x,y))*y;
}
 
//using namespace std;
//using namespace boost::multiprecision;
//using namespace __gnu_pbds;

int main(){
  using namespace std;
  int n;
  cin>>n;
  string s;
  cin>>s;
  typedef pair<string, string> P;
  map<P> mp;
  REP(k, 1<<n){
    string s1 = "", s2 = "";
    REP(i, n){
      if(k>>i&1){
        s1 += s[i];
      }else{
        s2 = s[i] + s2;
      }
    }
    mp[P(s1, s2)]++;
  }
  long long ans = 0;
  REP(k, 1<<n){
    string s1 = "", s2 = "";
    REP(i, n){
      if(k>>i&1){
        s1 = s[i + n] + s1;
      }else{
        s2 += s[i + n];
      }
    }
    ans += (long long)mp[P(s1, s2)];
  }
  cout << ans << endl;
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:76:8: error: wrong number of template arguments (1, should be at least 2)
   76 |   map<P> mp;
      |        ^
In file included from /usr/include/c++/14/map:63,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:152,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_map.h:102:11: note: provided for 'template<class _Key, class _Tp, class _Compare, class _Alloc> class std::map'
  102 |     class map
      |           ^~~
a.cc:86:7: error: no match for 'operator[]' (operand types are 'int' and 'P' {aka 'std::pair<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char> >'})
   86 |     mp[P(s1, s2)]++;
      |       ^
a.cc:98:25: error: no match for 'operator[]' (operand types are 'int' and 'P' {aka 'std::pair<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char> >'})
   98 |     ans += (long long)mp[P(s1, s2)];
      |                         ^
Language: C++

std::pair<std::__decay_and_strip<_T1>::__type, std::__decay_and_strip<_T2>::__type> make_pair<_T1, _T2>(_T1 &&__x, _T2 &&__y)
NB: DR 706.



Compiler output:
a.cc:1:6: error: 'pair' in namespace 'std' does not name a template type
    1 | std::pair<std::__decay_and_strip<_T1>::__type, std::__decay_and_strip<_T2>::__type> make_pair<_T1, _T2>(_T1 &&__x, _T2 &&__y)
      |      ^~~~
a.cc:1:1: note: 'std::pair' is defined in header '<utility>'; this is probably fixable by adding '#include <utility>'
  +++ |+#include <utility>
    1 | std::pair<std::__decay_and_strip<_T1>::__type, std::__decay_and_strip<_T2>::__type> make_pair<_T1, _T2>(_T1 &&__x, _T2 &&__y)
Language: C++

#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
#include <string>
#include <cmath>
#include <iomanip>

using namespace std;

#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define REP(i, n) FOR(i, 0, n)
#define SORT(c) sort((c).begin(), (c).end())

typedef long long ll;

int main()
{
    int n;
    string s;

    cin >> n >> s;

    ll res = 0;

    for (int i = 0; i < (1 << n); i++)
    {
        string lr = "", lb = "";

        for (int j = 0; j < n; j++)
        {
            if (i & (1 << j))
                lr += s[j];
            else
                lb += s[j];
        }

        ll dp[40][20];
        memset(dp, 0, sizeof(dp));

        dp[n * 2][0] = 1;

        for (int j = n * 2 - 1; j >= n; j--)
        {
            for (int k = 0; k <= lr.size(); k++)
            {
                dp[j][k] += (k > 0) * dp[j + 1][k - 1] * (s[j] == lr[k - 1]);
                dp[j][k] += dp[j + 1][k] * (s[j] == lb[(n * 2 - j) - k - 1]);
            }
        }

        res += dp[n][lr.size()];
    }

    cout << res << endl;

    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:39:9: error: 'memset' was not declared in this scope
   39 |         memset(dp, 0, sizeof(dp));
      |         ^~~~~~
a.cc:8:1: note: 'memset' is defined in header '<cstring>'; this is probably fixable by adding '#include <cstring>'
    7 | #include <iomanip>
  +++ |+#include <cstring>
    8 |
Language: C++

#include <iostream>
#include <string>
#include <random>
#include <map>
using namespace std;
typedef long long ll;

ll N;
ll rnd[18][256];

void func(string s, vector<map<ll, ll> >&v){
    for(ll i = 0; i < (1 << N); i++){
        ll hs = 0;
        int cnt = 0;
        for(ll j = 0, k = 1, front = 0, back = N - 1; j < N; j++, k <<= 1){
            if(i & k){
                hs ^= rnd[front][s[j]];
                front++;
                cnt++;
            }
            else{
                hs ^= rnd[back][s[j]];
                back--;
            }
        }
        v[cnt][hs]++;
    }
}

int main(){

    random_device rd;
    mt19937_64 mt(rd());
    for(int i = 0; i < 18; i++){
        for(int j = 'a'; j <= 'z'; j++){
            rnd[i][j] = mt();
        }
    }

    cin >> N;
    string s;
    cin >> s;

    string s1 = s.substr(0, N);
    string s2 = s.substr(N, N);
    reverse(s2.begin(), s2.end());
    
    vector<map<ll, ll> >v1(N + 1);
    vector<map<ll, ll> >v2(N + 1);

    func(s1, v1);
    func(s2, v2);

    ll ans = 0;
    for(int a = 0; a <= N; a++){
        for(map<ll, ll>::iterator it = v1[a].begin(); it != v1[a].end(); it++){
            ll key = (*it).first;
            ll value = (*it).second;
            ans += v2[a][key] * value;
        }
    }
    cout << ans << endl;

    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:46:5: error: 'reverse' was not declared in this scope
   46 |     reverse(s2.begin(), s2.end());
      |     ^~~~~~~
Language: C++

#include <bits/stdc++.h>

int main()
{
	int N;
	std::string S;
	std::cin >> N >> S;
	int limit{1 << N};
	std::vector<std::pair<std::string, std::string>> former(limit);
	for (int i{}; i < limit; i++)
	{
		for (int j{}; j < N; j++)
			if (i >> j & 1)
				former[i].first += S[j];
		for (int j{N - 1}; j >= 0; j--)
			if (~i >> j & 1)
				former[i].second += S[j];
	}
	std::sort(former.begin(), former.end());

	long long count{};
	for (int i{}; i < limit; i++)
	{
		std::pair<std::string, std::string> tmp;
		for (int j{}; j < N; j++)
			if (i >> j & 1)
				tmp.first += S[2 * N - 1 - j];
		for (int j{N - 1}; j >= 0; j--)
			if (~i >> j & 1)
				tmp.second += S[2 * N - 1 - j];
		count += std::upper_bound(former.begin(), former.end(), tmp) - std::lower_bound(former.begin(), former.end(), tmp);
	}
	printf("%lld\n", count);

	return 0;
}5

Compiler output:
a.cc:36:2: error: expected unqualified-id before numeric constant
   36 | }5
      |  ^
Language: C

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

int next_combination(int sub) {
        int x = sub & -sub, y = sub + x;
        return (((sub & ~y) / x) >> 1) | y;
}

int main(){
    int n;
    cin>>n;
    string s;
    cin>>s;
    int k=n;
    n*=2;
    long long ans=0;

    /*int n = 5;  // {0, 1, 2, 3, 4} の部分集合を考える
    int k = 3;// 部分集合のうち、要素数が3個の物を数える */
    

    for (int bit = (1LL<<k)-1;bit < (1LL<<n); bit = next_combination(bit)) {
        string red="",blue="";
        /* bit で表される集合の処理を書く */
        /*int cnt=0;
        for(int i=0;i<n;i++){
            if((bit>>i&1)) cnt++; //bitのi番目が1ならcnt++
        }*/

        for(int i=0;i<n;i++){
            if((bit>>i&1LL)){
                red+=s[i];
            }
            else blue+=s[i];
        }
        reverse(blue.begin(),blue.end());
        //cerr<<red<<"  "<<blue<<endl;
        if(red==blue) ans++;
    }
    cout<<ans;


}

Compiler output:
main.c:1:9: fatal error: bits/stdc++.h: No such file or directory
    1 | #include<bits/stdc++.h>
      |         ^~~~~~~~~~~~~~~
compilation terminated.
Language: C++


//#include "pch.h"
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>

#include <vector>
#include <set>
#include <map>
#include <iostream>
#include <utility>
#include <queue>
#include <algorithm>
#include <functional>
#include <string>

#define ll long long
#define fri(n) for(i=0;i<(n);i++)
#define frj(n) for(j=0;j<(n);i++)
#define min(p,q) ((p)<(q)?(p):(q))
#define max(p,q) ((p)>(q)?(p):(q))
#define swap(p,q) r=(p);(p)=(q);(q)=r
#define INF 1000000000000//10^12
#define INFINT 2000000001//2*10^9+1
#define ALL(a) (a).begin(),(a).end()

using namespace std;


struct kouzou_t{
	string str;	
	int idnum;

	bool operator<(const kouzou_t& another) const {
		//メンバ変数であるnum1で比較した結果を
		//この構造体の比較とする
		int x=str.compare(another.str);
		if(x==1) return 1;
		return 0;
	}
};


int main(void)
{
	//変数の宣言
	int n;
	char s[40];
//	string str;
	struct kouzou_t memo;
	vector<kouzou_t> dp;
	struct kouzou_t kouzou;
	int ng,ok;

	//よく使う変数
	int i,j,k,l;
	int flag=0;
	ll int ans=0;
	int count=0;
	int temp,temp1,temp2;
	int max,min;
	int len;
	int sum=0;



	//データの読み込み


	scanf("%d",&n);
//	scanf_s("%d",&n);

//	scanf("%s",&s);
	scanf_s("%s",&s,40);

//	for(i=1;i<=n;i++){
//		scanf("%lld %lld %d",&x[i],&y[i],&r[i]);
//		scanf_s("%lld %lld %d",&x[i],&y[i],&r[i]);
//	}
	
	//	printf("nは%dです\n", n);
	//	printf("データの読み込み終了\n");
	//実際の処理

	for(i=0;i<(1<<n);i++){
		temp=0;
		for(j=0;j<n;j++){
			if((i&(1<<j))==0){
				kouzou.str.push_back(s[j]);
				temp++;
			}
		}
		kouzou.str.push_back(',');
		for(j=0;j<n;j++){
			if((i&(1<<j))!=0){
				kouzou.str.push_back(s[j]);
			}
		}

//		printf("%s\n",kouzou.str.c_str());

		kouzou.idnum=1;
		dp.push_back(kouzou);
		kouzou.str.erase(kouzou.str.begin(),kouzou.str.end());
		
	}

	
/*	for(auto itr=dp.begin();itr!=dp.end();++itr){
		memo=*itr;
		printf("%s\n",memo.str.c_str());
	}
*/
	sort(dp.begin(),dp.end());

	for(i=0;i<(1<<n);i++){
		dp[i].idnum=i;
	}

/*	for(auto itr=dp.begin();itr!=dp.end();++itr){
		memo=*itr;
		printf("%s\n",memo.str.c_str());
	}
*/




	for(i=0;i<(1<<n);i++){
		for(j=0;j<n;j++){
			if((i&(1<<j))==0){
				kouzou.str.push_back(s[2*n-1-j]);
			}
		}
		kouzou.str.push_back(',');
		for(j=0;j<n;j++){
			if((i&(1<<j))!=0){
				kouzou.str.push_back(s[2*n-1-j]);
			}
		}

		ng=-1;
		ok=(1<<n);
		while(ok-ng>1){
//			printf("%d\n",dp[(ok+ng)/2].str.compare(kouzou.str));
			if(dp[(ok+ng)/2].str.compare(kouzou.str)>0){
				ng=(ok+ng)/2;
			}else{
				ok=(ok+ng)/2;
			}
		}
		ans=ans-ok;
		
		ng=-1;
		ok=(1<<n);
		while(ok-ng>1){
			if(dp[(ok+ng)/2].str.compare(kouzou.str)>=0){
				ng=(ok+ng)/2;
			}else{
				ok=(ok+ng)/2;
			}
		}
		ans=ans+ok;
		
		kouzou.str.erase(kouzou.str.begin(),kouzou.str.end());
	}


	//	printf("計算部分終了\n");

	//出力

	printf("%lld",ans);

	//	printf("結果の出力終了\n");


	return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:75:9: error: 'scanf_s' was not declared in this scope; did you mean 'scanf'?
   75 |         scanf_s("%s",&s,40);
      |         ^~~~~~~
      |         scanf
Language: C

#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
#define pb push_back
using namespace std;

typedef pair <int, int> pii;
typedef pair <string, string> pss;
typedef long long ll;

const int inf = 1e9 + 1;
const double eps = 1e-9;
const int MAXN = 18;

int n;
string s;
map <pss, int> m;
int sol;

int main(){

    cin >> n;
    cin >> s;

    for (int mask = 0; mask < (1<<n); mask++){
        string r = "", b = "";
        for (int i = 0; i < n; i++){
            if (mask & (1<<i)) r += s[i];
            else b += s[i];
        }
        reverse(b.begin(), b.end());
        m[mp(r, b)]++;
    }

    for (int mask = 0; mask < (1<<n); mask++){
        string r = "", b = "";
        for (int i = 0; i < n; i++){
            if (mask & (1<<i)) r += s[n+i];
            else b += s[n+i];
        }
        reverse(b.begin(), b.end());
        sol += m[mp(b, r)];
    }

    cout << sol;

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

#define pb push_back

const int mn=39;

int n;
char s[mn];

unordered_map<size_t,int> h;
hash<string> hs;

string t;
inline size_t gethash(string &s){
    return hs(s);
}

int main() {
    scanf("%d",&n);
    scanf("%s",s);

    ll ans=0;

    for(int i=0;i<(1<<n);i++){
        t.clear();
        for(int j=0;j<n;j++){
            if ((1<<j)&i) t+=s[j];
        }
        for(int j=n-1;j>=0;j--){
            if (((1<<j)&i)==0) t+=toupper(s[j]);
        }
        h[gethash(t)]++;
    }

    reverse(s,s+n*2);
    for(int i=0;i<(1<<n);i++){
        t.clear();
        for(int j=0;j<n;j++){
            if ((1<<j)&i) t+=s[j];
        }
        for(int j=n-1;j>=0;j--){
            if (((1<<j)&i)==0) t+=toupper(s[j]);
        }
        ans+=h[gethash(t)];
    }
    printf("%lld\n",ans);
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:23:5: error: 'll' was not declared in this scope
   23 |     ll ans=0;
      |     ^~
a.cc:45:9: error: 'ans' was not declared in this scope; did you mean 'abs'?
   45 |         ans+=h[gethash(t)];
      |         ^~~
      |         abs
a.cc:47:21: error: 'ans' was not declared in this scope; did you mean 'abs'?
   47 |     printf("%lld\n",ans);
      |                     ^~~
      |                     abs
Language: C++

#include<bits/stdc++.h>
using namespace std;
#define inf 1000000000
#define INF 1000000000000000
#define ll long long
#define ull unsigned long long
#define M 1000000007
#define P pair<int,int>
#define PLL pair<ll,ll>
#define FOR(i,m,n) for(int i=(int)m;i<(int)n;i++)
#define RFOR(i,m,n) for(int i=(int)m;i>=(int)n;i--)
#define rep(i,n) FOR(i,0,n)
#define rrep(i,n) RFOR(i,n,0)
#define all(a) a.begin(),a.end()
#define IN(a,n) rep(i,n){ cin>>a[i]; }
const int vx[4] = {0,1,0,-1};
const int vy[4] = {1,0,-1,0};
#define PI 3.14159265
#define F first
#define S seconnd
#define int ll
#define PB push_back

int n;
string s;
map<pair<string,string>,int> ma;
int ans=0;

void f(string t,string u,int m){
  if(m==n){
    ma[make_pair(t,u)]++;
    return;
  }

  f(t,u+s[m],m+1);
  f(t+s[m],u,m+1);
}


void g(string t,string u,int m){
  if(m==n{
    ans+=ma[make_pair(t,u)];
    return;
  }

  g(t,u+s[m],m+1);
  g(t+s[m],u,m+1);
}



signed main(){
  cin>>n>>s;

  string t="",u="";
  f(t,u,0);
  reverse(all(s));
  
  string a="",b="";
  g(a,b,0);

  cout<<ans<<endl;

}

Compiler output:
a.cc: In function 'void g(std::string, std::string, long long int)':
a.cc:41:10: error: expected ';' before '{' token
   41 |   if(m==n{
      |          ^
      |          ;
a.cc:46:18: error: expected ')' before ';' token
   46 |   g(t,u+s[m],m+1);
      |                  ^
      |                  )
a.cc:41:5: note: to match this '('
   41 |   if(m==n{
      |     ^
a.cc:46:4: error: could not convert 'g(std::__cxx11::basic_string<char>(t), std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, _CharT) [with _CharT = char; _Traits = char_traits<char>; _Alloc = allocator<char>](((int)s.std::__cxx11::basic_string<char>::operator[](((std::__cxx11::basic_string<char>::size_type)m)))), (m + 1))' from 'void' to 'bool'
   46 |   g(t,u+s[m],m+1);
      |   ~^~~~~~~~~~~~~~
      |    |
      |    void
Language: C++

/*
-----------------------------------------------------------------------------
Author :            ---------------------------------------------------------
    UTKAR$H $AXENA  ---------------------------------------------------------
    GOOGLE          ---------------------------------------------------------
-----------------------------------------------------------------------------
*/
#include <iostream>
#include <map>
#include <set>
#include <vector>
using namespace std;
#define fre freopen("0.in", "r", stdin), freopen("0.out", "w", stdout)
#define abs(x) ((x) > 0 ? (x) : -(x))
#define MOD 1000000007
#define LL signed long long int
#define ps(x) push_back(x)
#define scan(x) scanf("%d", &x)
#define print(x) printf("%d\n", x)
#define scanll(x) scanf("%lld", &x)
#define printll(x) printf("%lld\n", x)
#define boost ios_base::sync_with_stdio(0)
// vector<int> g[2*100000+5];int par[2*100000+5];
map<pair<LL, LL>, LL> g1, g2;
void getSet(map<pair<LL, LL>, LL> &g, string S) {
  int n = S.size();
  // cout << S << endl;
  LL p = 31;
  for (int mask = 0; mask < (1 << n); ++mask) {
    LL p1 = 1, p2 = 1;
    for (int i = 0; i < n; ++i) {
      if (mask & (1 << i)) {
        p1 = p1 * p + (S[i] - 'a');
        p1 %= MOD;
      } else {
        p2 = p2 * p + (S[i] - 'a');
        p2 %= MOD;
      }
    }
    g[{p1, p2}]++;
  }
}
int main() {
  // fre;
  int N;
  cin >> N;
  string S;
  cin >> S;
  getSet(g1, S.substr(0, N));
  string x = S.substr(N, N);
  reverse(x.begin(), x.end());
  getSet(g2, x);
  LL ans = 0;
  for (auto &p : g1) {
    if (g2.find(p.first) != g2.end()) {
      // cout << p.first.first << ' ' << p.first.second << ' ' << p.second <<
      // endl;
      ans += p.second * 1LL * g2[p.first];
    }
  }
  cout << ans;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:51:3: error: 'reverse' was not declared in this scope
   51 |   reverse(x.begin(), x.end());
      |   ^~~~~~~
Language: C++

#include <iostream>
#include <stdint.h>
#include <string>
#include <utility>
#include <map>

using namespace::std;

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

	string str;
	cin >> str;

	map<pair<string, string>, int> mp;
	map<pair<string, string>, int> mq;

	for (int i = 0; i < (1 << N); i++)
	{
		string u = "";
		string v = "";

		for (int j = 0; j < N; j++)
		{
			if (i & (1 << j))
				u.push_back(str[j]);
			else
				v.push_back(str[j]);
		}

		reverse(v.begin(), v.end());
		mp[make_pair(u, v)]++;
	}

        for (int i = 0; i < (1 << N); i++)
        {
                string u = "";
                string v = "";

                for (int j = 0; j < N; j++)
                {
                        if (i & (1 << j))
                                u.push_back(str[N + j]);
                        else
                                v.push_back(str[N + j]);
                }
		
		reverse(v.begin(), v.end());
		mq[make_pair(v, u)]++;
        }

	int64_t ans = 0;
	for (map<pair<string, string>, int>::iterator it = mp.begin(); it != mp.end(); it++)
	{
		pair<string, string> s = it->first;
		int64_t x = it->second;
		int64_t y = mq[s];

		ans += x * y;
	}

	cout << ans << endl;

	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:33:17: error: 'reverse' was not declared in this scope
   33 |                 reverse(v.begin(), v.end());
      |                 ^~~~~~~
a.cc:50:17: error: 'reverse' was not declared in this scope
   50 |                 reverse(v.begin(), v.end());
      |                 ^~~~~~~
Language: C++

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<string>
#include<stack>
#include<queue>
#include<vector>
#include<algorithm>
#include<iomanip>
#include<utility>
#include<set>
#include<unordered_set>
#include<map>
#include<unordered_map>
typedef long long int ll;
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) for(int i=0;i<signed(n);i++)
#define EREP(i,n) for(int i=1;i<=signed(n);i++)
#define ALL(a) (a).begin(),(a).end()
using namespace std;
//#define EVEL 1
#ifdef EVEL
#define DEB(X) cout << #X << ":" <<X<<" " ;
#define TF(f) f ? cout<<"true  " : cout<<"false ";
#define END cout<<"\n";
#else
#define DEB(X) {}
#define TF(f) {}
#define END {}
#endif
constexpr int MOD = 1000000007;
constexpr ll INF = 50000000000000000;
typedef std::pair<int,int> P;
constexpr ll SIZE= 100010;
namespace std {
    template <>
    class hash<std::pair<string, string>> {
    public:
        size_t operator()(const std::pair<string, string>& x) const{
            return hash<string>()(x.first) ^ hash<string>()(x.second);
        }
    };
}
ll N,A[100010],B[SIZE];
string S,T,q;
ll ans=0,sum=0,wa=0;
unordered_map<pair<string,string>,ll> M;
int main() {
    std::ios_base::sync_with_stdio(false);
    cin>>N>>q;
    S=q.substr(0,N),T=q.substr(N,N);
    reverse(ALL(T));
    REP(Bit,1<<N){
        string s="",t="";
        // if(Bit==0||Bit==(1<<N)-1)continue;
        REP(i,N){
            if(Bit&(1<<i))s+=S[i];
            else t+=S[i];
        }
        reverse(ALL(t));
        DEB(s)DEB(t)END
        M[{s,t}]++;
    }
    REP(Bit,1<<N){
        string s="",t="";
        // if(Bit==0||Bit==(1<<N)-1)continue;
        REP(i,N){
            if(Bit&(1<<i))s+=T[i];
            else t+=T[i];
        }
        DEB(s)DEB(t)DEB(M[make_pair(s,t)])END
        ans+=M[{t,s}];
    }
    cout<<ans<<endl;
    return 0;

Compiler output:
a.cc: In function 'int main()':
a.cc:76:14: error: expected '}' at end of input
   76 |     return 0;
      |              ^
a.cc:49:12: note: to match this '{'
   49 | int main() {
      |            ^
Language: Java

#include <map>
#include <iostream>
using namespace std;
typedef pair<string,string> pa;
int main() {
    int n;
    long long ans = 0;
    string s;
    map<pa,int> mp;
    cin>>n>>s;
    for(int i = 0;i < 1 << n;i ++) {
        string a = "";
        string b = "";
        for(int j = 0;j < n;j ++) {
            if(i >> j & 1)a += s[j];
            else b += s[j];
        }
        mp[pa(a,b)] ++;
    }
    for(int i = 0;i < 1 << n;i ++) {
        string a = "";
        string b = "";
        for(int j = 0;j < n;j ++) {
            if(i >> j & 1)a += s[j];
            else b += s[j];
        }
        ans += mp[pa(a,b)];
    }
    cout<<ans;
}


Compiler output:
Main.java:1: error: illegal character: '#'
#include <map>
^
Main.java:2: error: illegal character: '#'
#include <iostream>
^
Main.java:4: error: class, interface, enum, or record expected
typedef pair<string,string> pa;
^
Main.java:7: error: not a statement
    long long ans = 0;
    ^
Main.java:10: error: not a statement
    cin>>n>>s;
          ^
Main.java:29: error: not a statement
    cout<<ans;
        ^
Main.java:5: error: unnamed classes are a preview feature and are disabled by default.
int main() {
^
  (use --enable-preview to enable unnamed classes)
Main.java:7: error: ';' expected
    long long ans = 0;
        ^
8 errors
Language: C++

#include <vector>
#include <map>
#include <string>
#include <tuple>

using namespace std;

int N;
char S[50];

map<tuple<int, int, string>, long long> memo;
long long f(int L, int R, string s)
{
	if(s.size() > R-L) 	return 0;
	if(L==R) 			return s.empty();

	auto e = tuple<int, int, string>(L, R, s);
	if(memo.count(e)) 	return memo[e];

	long long v = 0;
	if(!s.empty())
	{
		if(S[L] == s.back())
			v += f(L+1, R, s.substr(0,s.size()-1));
		for(int i=L+1; i<R;++i)
			if(S[L] == S[i])
				v += f(L+1,i,string(S+i+1,S+R)+s);
	}
	else
	{
		for(int i=L+1; i<R;++i)
			if(S[L] == S[i])
				v += 2*f(L+1,i,string(S+i+1,S+R));
	}
	return memo[e]=v;
}


int main() {
	scanf("%d", &N);
	scanf("%s", S);
	printf("%lld\n", go(0,2*N,string()));
}

Compiler output:
a.cc: In function 'int main()':
a.cc:42:26: error: 'go' was not declared in this scope
   42 |         printf("%lld\n", go(0,2*N,string()));
      |                          ^~
Language: C++

#include<stdio.h>
#include<string.h>
#define N 55
#define LL long long
LL s[N][N];
char a[N],b[N],c[N];

int main(){
	int n;
	LL ans;
	scanf("%d%s",&n,a);
	ans=0;
	for(t=0;t<(1<<n);++t){
		int k1=0,k2=0;
		for(int j=0;j<n;++j){
			if(t&1<<j)b[k1++]=a[j];
			else c[k2++]=a[j];
        }
		b[k1]=c[k2]='\0';
		memset(s,0,sizeof(s));
        s[0][0]=1;
		for(int i=0;i<=k1;++i){
			for(int j=0;j<=k2;++j){
				if(a[n*2-1-i-j]==b[i])
				s[i+1][j]+=s[i][j];
				if(a[n*2-1-i-j]==c[j])
				s[i][j+1]+=s[i][j];
			}
		}
		ans+=s[k1][k2];
	}
	printf("%lld\n",ans);
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:13:13: error: 't' was not declared in this scope
   13 |         for(t=0;t<(1<<n);++t){
      |             ^
Language: C++

#include<stdio.h>
#include<string.h>
#define N 55
#define LL long long
LL s[N][N];
char a[N],b[N],c[N];

int main(){
	int n;
	LL ans;
	scanf("%d%s",&n,a);
	ans=0;
	for(t=0;t<(1<<n);++t){
		k1=k2=0;
		for(int j=0;j<n;++j){
			if(t&1<<j)b[k1++]=a[j];
			else c[k2++]=a[j];
        }
		b[k1]=c[k2]='\0';
		memset(s,0,sizeof(s));
        s[0][0]=1;
		for(int i=0;i<=k1;++i){
			for(int j=0;j<=k2;++j){
				if(a[n*2-1-i-j]==b[i])
				s[i+1][j]+=s[i][j];
				if(a[n*2-1-i-j]==c[j])
				s[i][j+1]+=s[i][j];
			}
		}
		ans+=s[k1][k2];
	}
	printf("%lld\n",ans);
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:13:13: error: 't' was not declared in this scope
   13 |         for(t=0;t<(1<<n);++t){
      |             ^
a.cc:14:17: error: 'k1' was not declared in this scope
   14 |                 k1=k2=0;
      |                 ^~
a.cc:14:20: error: 'k2' was not declared in this scope
   14 |                 k1=k2=0;
      |                    ^~
Language: C++

#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstring>
using namespace std;
const int N = 6e5+5;
const int M = 1e5+5;
const int INF = 0x3f3f3f3f;
typedef long long ll;
#define lson l, m, rt<<1
#define rson m+1, r, rt<<1|1

char seq[N];
int has[30];
ll ans = 0;

int nx[M][27];
int sum[M];
int tot;
void insert(string tmp) {
//	cout << tmp << endl;
	int rt = 0;
	for(int i = 0; i < tmp.length(); ++i) {
		int tar = tmp[i] - 'a';
		if(nx[rt][tar] == -1) {
			nx[rt][tar] = ++tot;
			sum[tot] = 0;
		}
		rt = nx[rt][tar];
	}
	sum[rt] ++;
}
int search(string tmp) {
//	cout << "hh" << tmp << endl;
	int rt = 0;
	for(int i = 0; i < tmp.length(); ++i) {
		int tar = tmp[i] - 'a';
		if(nx[rt][tar] == -1) {
			return 0;
		}
		rt = nx[rt][tar];
	}
	return sum[rt];
}


int main() {
	int n;
	while(~scanf("%d", &n)) {
		memset(nx, -1, sizeof(nx));
		sum[0] = 0;
		tot = 0;
		memset(has, 0, sizeof(has));


		scanf("%s", seq);
		for(int i = 0; i < n; ++i) {
			has[seq[i] - 'a'] ++;
		}
		bool flag = true;
		for(int i = n; i < 2*n && flag; ++i) {
			has[seq[i] - 'a'] --;
			if(has[seq[i] - 'a'] == -1) {
				flag = false;
			}
		}
		if(!flag) {
			printf("0\n");
			continue;
		}

		
		int largeNum = 1<<n;
		for(int i = 0; i < largeNum; ++i) {
			string tmp1; string tmp2;
			for(int j = 0; j < n; ++j) {
				if( (i >> j) & 1 ) {
					tmp1 += seq[j];
				} else tmp2 += seq[j];
			}
			tmp1 += 'z'+1;
			tmp1 += tmp2;
			insert(tmp1);
		}

		ll ans = 0;
		for(int i = 0; i < largeNum; ++i) {
			string tmp1, tmp2;
			for(int j = 0; j < n; ++j) {
				if( (i >> j) & 1 ) {
					tmp1 += seq[j + n];
				} else tmp2 += seq[j + n];
			}
			reverse(tmp1.begin(), tmp1.end());
			reverse(tmp2.begin(), tmp2.end());
			tmp1 += 'z'+1;
			tmp1 += tmp2;

			ans += search(tmp1);
		}
		printf("%lld\n", ans);
	}
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:94:25: error: 'reverse' was not declared in this scope
   94 |                         reverse(tmp1.begin(), tmp1.end());
      |                         ^~~~~~~
Language: C++

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

using ll = long long;

constexpr ll mod = 100055128505716009ll;

vector<pair<ll, ll>> make_hashes(string str){
    vector<pair<ll, ll>> v;
    v.emplace_back(0, 0);

    for(auto ch : str){
        const int sz = v.size();
        for(int i = 0; i < sz; ++i){
            ll x, y;
            tie(x, y) = v[i];
            v[i] = make_pair((3ll * x + ch)%mod, y);
            v.emplace_back(x, (3ll * y + ch)%mod); } }

    return  v; }

int main(){
    int n;
    cin >> n;
    string str;
    cin >> str;

    string left, right;

    for(int i = 0; i < n; ++i){
        left.push_back(str[i]);
        right.push_back(str[2 * n - i - 1]); }

    auto h1 = make_hashes(left), h2 = make_hashes(right);

    sort(begin(h1), end(h1));

    long long rez = 0;

    for(auto x : h2)
        rez += upper_bound(begin(h1), end(h1), x) - lower_bound(begin(h1), end(h1), x);

    cout << rez << endl;
    return 0; }


Compiler output:
a.cc: In function 'int main()':
a.cc:38:5: error: 'sort' was not declared in this scope; did you mean 'short'?
   38 |     sort(begin(h1), end(h1));
      |     ^~~~
      |     short
a.cc:43:16: error: 'upper_bound' was not declared in this scope
   43 |         rez += upper_bound(begin(h1), end(h1), x) - lower_bound(begin(h1), end(h1), x);
      |                ^~~~~~~~~~~
Language: C++

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
template<class T> using vt = vector<T>;
template<class T> using vvt = vector<vt<T>>;
template<class T> using ttt = tuple<T,T>;
using tii = tuple<int,int>;
using vi = vector<int>;
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define pb push_back
#define mt make_tuple
#define ALL(a) (a).begin(),(a).end()
#define FST first
#define SEC second
#define DEB cerr<<"!"<<endl
#define SHOW(a,b) cerr<<(a)<<" "<<(b)<<endl
#define DIV int(1e9+7)
const int INF = (INT_MAX/2);
const ll LLINF = (LLONG_MAX/2);
const double eps = 1e-8;
//const double PI = M_PI;  
inline ll pow(ll x,ll n,ll m){ll r=1;while(n>0){if((n&1)==1)r=r*x%m;x=x*x%m;n>>=1;}return r%m;}
inline ll lcm(ll d1, ll d2){return d1 / __gcd(d1, d2) * d2;}

/*Coding Space*/
int n; string s;

using tss = tuple<string,string>;
unoredered_map<tss,ll> ltable;
unoredered_map<tss,ll> rtable;
int main(){
  cin >> n >> s;
  rep(i,(1<<n)){
    string lin1 = "",lin2 = "", rin1 ="", rin2 = "";
    rep(j,n){
      if(i&(1 << j)){
        lin1 += s[j];
        rin1 += s[j+n];
      }else{
        lin2 += s[j];
        rin2 += s[j+n];
      }
    }
    ltable[tss{lin1,lin2}]++;
    rtable[tss{rin1,rin2}]++;
  }
  ll ans = 0;
  for(auto ss: ltable){
    string a,b; tie(a,b) = ss.FST;
    string ta = a,tb = b;
    reverse(ALL(ta)),reverse(ALL(tb));
    ans += rtable[tss{ta,tb}]*ss.SEC;
    //cerr << ans << " " << a << " " << b << endl;
  }
  cout << ans << endl;
}


Compiler output:
a.cc:29:1: error: 'unoredered_map' does not name a type
   29 | unoredered_map<tss,ll> ltable;
      | ^~~~~~~~~~~~~~
a.cc:30:1: error: 'unoredered_map' does not name a type
   30 | unoredered_map<tss,ll> rtable;
      | ^~~~~~~~~~~~~~
a.cc: In function 'int main()':
a.cc:44:5: error: 'ltable' was not declared in this scope; did you mean 'mutable'?
   44 |     ltable[tss{lin1,lin2}]++;
      |     ^~~~~~
      |     mutable
a.cc:45:5: error: 'rtable' was not declared in this scope; did you mean 'mutable'?
   45 |     rtable[tss{rin1,rin2}]++;
      |     ^~~~~~
      |     mutable
a.cc:48:16: error: 'ltable' was not declared in this scope; did you mean 'mutable'?
   48 |   for(auto ss: ltable){
      |                ^~~~~~
      |                mutable
a.cc:52:12: error: 'rtable' was not declared in this scope; did you mean 'mutable'?
   52 |     ans += rtable[tss{ta,tb}]*ss.SEC;
      |            ^~~~~~
      |            mutable
Language: C++

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

int N; string S; map<pair<string, string>, int>M;
long long ret = 0;

int main() {
	cin >> N >> S;
	for (int i = 0; i < (1 << N); i++) {
		string T1 = "", T2 = "";
		for (int j = 0; j < N; j++) {
			if ((i / (1 << j)) % 2 == 0) T1 += S[N + j];
			else T2 += S[N + j];
		}
		M[make_pair(T1, T2)]++;
	}
	for (int i = 0; i < (1 << N); i++) {
		string T1 = "", T2 = "";
		for (int j = 0; j < N; j++) {
			if ((i / (1 << j)) % 2 == 0) T1 += S[j];
			else T2 += S[j];
		}
		reverse(T1.begin(), T1.end());
		reverse(T2.begin(), T2.end());
		ret += M[make_pair(T2, T1)];
	}
	cout << ret << endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:25:17: error: 'reverse' was not declared in this scope
   25 |                 reverse(T1.begin(), T1.end());
      |                 ^~~~~~~
Language: C++

#define _CRT_SECURE_NO_WARNINGS
#define forn(i, a, n) for(int i = a; i < n; ++i)
#define pb push_back
#define mp make_pair
//#define f first
//#define sex second

#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <stack>
#include <set>
#include <ostream>
#include <queue>
#include <functional>
#include <sstream>
#include <map>

using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> pll;
#pragma comment(linker, "/STACK:228228000")
const ll mod = 998244353228;

ll n;
string s;

ll res(string s)
{
	ll mark[40];
	queue<pair<char, ll> > q;
	q.push(mp(s[0], 0));
	while(!q.empty())
	{
		pair<char, ll> v;
		v = q.front();
		q.pop();
		if (mark[v.second])
			continue;
		while()
	}
}
int main()
{
	/*

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

	cin >> n;
	cin >> s;


	return 0;
}

Compiler output:
a.cc: In function 'll res(std::string)':
a.cc:42:23: error: expected primary-expression before ')' token
   42 |                 while()
      |                       ^
a.cc:43:9: error: expected primary-expression before '}' token
   43 |         }
      |         ^
a.cc:44:1: warning: no return statement in function returning non-void [-Wreturn-type]
   44 | }
      | ^
Language: C++

#include <iostream>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <cstdio>
#include <utility>
#include <algorithm>
#include <iomanip>
using std::cin;
using std::cout;
using std::endl;

std::string nr;
std::string nb;
int s;
long long answer=0;

struct dfsinfo{
    bool used[36]={};
    int depth;
    int count;
};

void dfs(dfsinfo info){
    if(info.depth==2*s-1){
        int count;
        for(int i=0;i<2*s;i++){
            if(info.used[i])count++;
        }
        if(count!=s) return;
        std::string r;
        std::string b;
        for(int i=0;i<2*s;i++){
            if(info.used[i])r+=nr[i];
        }
        for(int i=2*s-1;i>=0;i++){
            if(!info.used[i])b+=nr[i];
        }
        if(r==b) answer++;
        return;
    }
    info.used[info.depth]=1;
    info.depth++;
    count++;
    if(count<=n)dfs(info);
    info.used[info.depth-1]=0;
    count--;
    dfs(info);
}


int main(void)
{
    cout << std::fixed << std::setprecision(10);
    cin>>s>>nr;
    dfsinfo pushinfo;
    dfs(pushinfo);
    cout<<answer<<endl;

    

    return 0;
}


Compiler output:
a.cc: In function 'void dfs(dfsinfo)':
a.cc:45:5: error: 'count' was not declared in this scope; did you mean 'std::count'?
   45 |     count++;
      |     ^~~~~
      |     std::count
In file included from /usr/include/c++/14/algorithm:86,
                 from a.cc:8:
/usr/include/c++/14/pstl/glue_algorithm_defs.h:101:1: note: 'std::count' declared here
  101 | count(_ExecutionPolicy&& __exec, _ForwardIterator __first, _ForwardIterator __last, const _Tp& __value);
      | ^~~~~
a.cc:46:15: error: 'n' was not declared in this scope
   46 |     if(count<=n)dfs(info);
      |               ^
Language: C++

#include<bits/stdc++.h>
using namespace std;
int main()
{
	int N;
	cin>>N;
	int a[N];
	int ans=0;
	int d;
	for(int i=0;i<N;i++)
	{
		cin>>a[i];
		a[i]=2
		for(int x=0;x<a[i];x++)
		{
			a[i]=2*a[i];
		}
		for(int y=0;y<N;y++)
		{
			d=a[i]+a[i+1];
		}
		cout<<d;
		return 0;
		
	}
 } 

Compiler output:
a.cc: In function 'int main()':
a.cc:13:23: error: expected ';' before 'for'
   13 |                 a[i]=2
      |                       ^
      |                       ;
   14 |                 for(int x=0;x<a[i];x++)
      |                 ~~~    
a.cc:14:29: error: 'x' was not declared in this scope
   14 |                 for(int x=0;x<a[i];x++)
      |                             ^
Language: C++

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

typedef long long ll;

using namespace std;

ll solve(string a, string b, string r, string ar, string br) {
    // cout << a << " : " << b << " : " << r << " : " << ar << " : " << br << endl;
    if (r.empty()) {
        a += ar;
        reverse(br.begin(), br.end());
        b += br;
        return (a == b);
    }

    ll sum = 0;
    for (int i = 0; i < r.size(); ++i) {
        string newR = r, newBr = r, newA = a;
        newA += r.at(i);
        newR.erase(newR.begin(), newR.begin() + i + 1);
        newBr.erase(newBr.begin() + i, newBr.end());
        newBr = newBr + br;
        for (int j = newR.size() - 1; j >= 0; --j) {
            // cout << i << " " << j << endl;
            if (newR.at(j) != newA.back()) continue;
            string newerR = newR, newB = b, newAr = newR;
            newB += newR.at(j);
            newerR.erase(newerR.begin() + j, newerR.end());
            newAr.erase(newAr.begin(), newAr.begin() + j + 1);
            newAr = ar + newAr;
            sum += solve(newA, newB, newerR, newAr, newBr);
        }
    }
    return sum;
}

int main() {
    int n;
    string s;
    vector<int> m(26);
    cin >> n >> s;
    cout << solve("", "", s, "", "") << endl;
    return 0;
}

Compiler output:
a.cc: In function 'll solve(std::string, std::string, std::string, std::string, std::string)':
a.cc:13:9: error: 'reverse' was not declared in this scope
   13 |         reverse(br.begin(), br.end());
      |         ^~~~~~~
Language: C++

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

long long n;
char S[36 + 10];

int bad[36 + 10];

char aa[36 + 10];

long long dp[36 + 10][36 + 10];

map<string,long long> res;

long long solve() {
   int ii = 0;
   for(int i = 0; i < 2*n; i++) {
      if(bad[i] == 1) aa[ii++] = S[i];
      if(!bad[i]) return;
   }
   if(ii != n) return 0;
   aa[ii] = 0;
   if(res.count(aa)) return 0;
   ii = 0;
   for(int i = 2*n-1; i >= 0; i--) {
      if(bad[i] == 2) {
         if(aa[ii++] != S[i]) return 0;
      }
   }
   if(ii != n) return 0;


   memset(dp, 0, sizeof dp);
   dp[n][n] = 1;
   for(int i = n; i >= 0; i--) {
      for(int j = n; j >= 0; j--) {
         if(i == n && j == n) continue;
         dp[i][j] = 0;
         if(i < n && aa[i] == S[i+j]) dp[i][j] += dp[i+1][j];
         if(j < n && aa[n-j-1] == S[i+j]) dp[i][j] += dp[i][j+1];
      }
   }
   return res[aa] = dp[0][0];
}

long long work() {
   for(int st = 0; st < (1 << n); st++) {
      memset(bad, 0, sizeof bad);
      bool sad = false;
      int ya = 2*n-1, yb = 2*n-1;
      for(int i = 0; i < n; i++) {
         if(st & (1 << i)) {
            bad[i] = 1;
            while(ya >= 0 && (bad[ya] || S[ya] != S[i])) ya--;
            if(ya < 0) {
               sad = true;
               break;
            }
            bad[ya] = 2;
         } else {
            bad[i] = 2;
            while(yb >= 0 && (bad[yb] || S[yb] != S[i])) yb--;
            if(yb < 0) {
               sad = true;
               break;
            }
            bad[yb] = 1;
         }
      }
      if(sad) continue;
      solve();
   }
   long long rs = 0;
   for(auto& it : res) rs += it.second;
   return rs;
}

int main() {
   scanf("%lld%s", &n, S);
   printf("%lld\n", work());
}


Compiler output:
a.cc: In function 'long long int solve()':
a.cc:19:19: error: return-statement with no value, in function returning 'long long int' [-fpermissive]
   19 |       if(!bad[i]) return;
      |                   ^~~~~~
Language: C


#include<map>
#include <iostream>
#include<vector>
#include <algorithm>
using namespace std;
#define rep(i,n) for (int (i)=(0);(i)<(long long)(n);++(i))
using ll = long long;
using P = pair<int, int>;
#define fs first
#define sc second
using namespace std;

template<class T> void vin(vector<T>& v, int n) {
    v.resize(n);
    for (int i = 0; i < n; ++i) {
        cin >> v[i];
    }
}

int n;
string s;
map<int, map<string, map<string, ll>>> dp;
map<int, map<string, map<string, bool>>> flag;

ll solve(int idx, string r, string b) {
    if (idx >= n*2) {
        reverse(b.begin(), b.end());
        if (r == b) return 1;
        else return 0;
    }
    if (flag[idx][r][b]) return dp[idx][r][b];
    flag[idx][r][b] = true;
    ll res = 0;
    if (idx < n) {
        res += solve(idx+1, r+s[idx], b);
        res += solve(idx+1, r, b+s[idx]);
    }
    else {
        //
        if (r.size()+1 <= n and s[idx] == b[n-r.size()-1]) res += solve(idx+1, r+s[idx], b);
        if (b.size()+1 <= n and s[idx] == r[n-b.size()-1]) res += solve(idx+1, r, b+s[idx]);
    }
    return (dp[idx][r][b] = res);
}

int main() {
    cin >> n >> s;
    cout << solve(0, "", "") << endl;
    return 0;
}


Compiler output:
main.c:2:9: fatal error: map: No such file or directory
    2 | #include<map>
      |         ^~~~~
compilation terminated.
Language: C++

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

typedef pair<string,string>P;

int n,ans;
string s;
map<pair<string,string> ,int>M;


signed main(){
	cin>>n>>s;
	string t=s.substr(n);
	for(int i=0;i<(1<<n);i++){
		int x=__builtin_popcount(i);
		string y="",z="";
		for(int j=0;j<n;j++)if((1<<j)&i)y+=t[j];
			else z+=t[j];
		reverse(y.begin(),y.end());
		reverse(z.begin(),z.end());
		M[P(y,z)]++;
	}
	t=s.substr(0,n);
	for(int i=0;i<(1<<n);i++){
		int x=__builtin_popcount(i);
		int z=n-x;
		string y="",Z="";
		for(int j=0;j<n;j++)if((1<<j)&i)y+=t[j];
			else Z+=t[j];
		if(y>Z)swap(y,Z);
		if(y.size()==1&&Z.size()==1){
			ans+=M[P(y,Z)];
			ans+=M[P(Z,y)];
		}
		else if(y.size()==1&&Z.size()!=1){
			ans+=M[P(y,Z)];
			ans+=M[P(Z,y)];
		}
		else{
			ans+=M[P(y,Z)];
			ans+=M[P(Z,y)];
		}
	}
	cout<<ans/2<<endl;
}#include <bits/stdc++.h>
#define int long long
using namespace std;

typedef pair<string,string>P;

int n,ans;
string s;
map<pair<string,string> ,int>M;


signed main(){
	cin>>n>>s;
	string t=s.substr(n);
	for(int i=0;i<(1<<n);i++){
		int x=__builtin_popcount(i);
		string y="",z="";
		for(int j=0;j<n;j++)if((1<<j)&i)y+=t[j];
			else z+=t[j];
		reverse(y.begin(),y.end());
		reverse(z.begin(),z.end());
		M[P(y,z)]++;
	}
	t=s.substr(0,n);
	for(int i=0;i<(1<<n);i++){
		int x=__builtin_popcount(i);
		int z=n-x;
		string y="",Z="";
		for(int j=0;j<n;j++)if((1<<j)&i)y+=t[j];
			else Z+=t[j];
		if(y>Z)swap(y,Z);
		if(y.size()==1&&Z.size()==1){
			ans+=M[P(y,Z)];
			ans+=M[P(Z,y)];
		}
		else if(y.size()==1&&Z.size()!=1){
			ans+=M[P(y,Z)];
			ans+=M[P(Z,y)];
		}
		else{
			ans+=M[P(y,Z)];
			ans+=M[P(Z,y)];
		}
	}
	cout<<ans/2<<endl;
}

Compiler output:
a.cc:46:2: error: stray '#' in program
   46 | }#include <bits/stdc++.h>
      |  ^
a.cc:46:3: error: 'include' does not name a type
   46 | }#include <bits/stdc++.h>
      |   ^~~~~~~
a.cc:52:5: error: redefinition of 'long long int n'
   52 | int n,ans;
      |     ^
a.cc:7:5: note: 'long long int n' previously declared here
    7 | int n,ans;
      |     ^
a.cc:52:7: error: redefinition of 'long long int ans'
   52 | int n,ans;
      |       ^~~
a.cc:7:7: note: 'long long int ans' previously declared here
    7 | int n,ans;
      |       ^~~
a.cc:53:8: error: redefinition of 'std::string s'
   53 | string s;
      |        ^
a.cc:8:8: note: 'std::string s' previously declared here
    8 | string s;
      |        ^
a.cc:54:30: error: redefinition of 'std::map<std::pair<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char> >, long long int> M'
   54 | map<pair<string,string> ,int>M;
      |                              ^
a.cc:9:30: note: 'std::map<std::pair<std::__cxx11::basic_string<char>, std::__cxx11::basic_string<char> >, long long int> M' previously declared here
    9 | map<pair<string,string> ,int>M;
      |                              ^
a.cc:57:8: error: redefinition of 'int main()'
   57 | signed main(){
      |        ^~~~
a.cc:12:8: note: 'int main()' previously defined here
   12 | signed main(){
      |        ^~~~
Language: C++

#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#define pc(x) __builtin_popcount(x)
typedef long long lnt;
const lnt INF = (~0U) >> 2;
const lnt INFLL = (~0ULL) >> 2;
lnt n, ans;
char buf[40], tmp1[40], tmp2[40], f[20][40][40];
lnt main() {
	scanf("%lld", &n);
	scanf("%s", buf);
	for (lnt i = 0; i < (1 << n); i++) {
		lnt len1 = 0, len2 = 0;
		for (lnt j = 0; j < n; j++) {
			if ((i >> j) & 1) {
				tmp1[++len1] = buf[j];
			} else {
				tmp2[++len2] = buf[j];
			}
		}
		std::reverse(tmp1 + 1, tmp1 + len1 + 1);
		std::reverse(tmp2 + 1, tmp2 + len2 + 1);
		memset(f, 0, sizeof(f));
		f[0][0][0] = 1;
		for (lnt i = 0; i < n; i++) {
			for (lnt j = 0; j <= len1; j++) {
				for (lnt k = 0; k <= len2; k++) {
					if (j < len1 && buf[i + n] == tmp1[j + 1])
						f[i + 1][j + 1][k] += f[i][j][k];
					if (k < len2 && buf[i + n] == tmp2[k + 1])
						f[i + 1][j][k + 1] += f[i][j][k];
				}
			}
		}
		ans += f[n][len1][len2];
	}
	printf("%lld\n", ans);
	return 0;
}

Compiler output:
a.cc:11:1: error: '::main' must return 'int'
   11 | lnt main() {
      | ^~~
Language: C++

//Relive your past life.
//Face your demons.
//The past is never dead,it is not even past.
//The memories are not only the key to the past but...also to the future.
//coded in Rusty Lake
#include<cmath>
#include<math.h>
#include<ctype.h>
#include<algorithm>
#include<bitset>
#include<cassert>
#include<cctype>
#include<cerrno>
#include<cfloat>
#include<ciso646>
#include<climits>
#include<clocale>
#include<complex>
#include<csetjmp>
#include<csignal>
#include<cstdarg>
#include<cstddef>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<ctime>
#include<cwchar>
#include<cwctype>
#include<deque>
#include<exception>
#include<fstream>
#include<functional>
#include<iomanip>
#include<ios>
#include<iosfwd>
#include<iostream>
#include<istream>
#include<iterator>
#include<limits>
#include<list>
#include<locale>
#include<map>
#include<memory>
#include<new>
#include<numeric>
#include<ostream>
#include<queue>
#include<set>
#include<sstream>
#include<stack>
#include<stdexcept>
#include<streambuf>
#include<string>
#include<typeinfo>
#include<utility>
#include<valarray>
#include<vector>
#include<string.h>
#include<stdlib.h>
#include<stdio.h>
#define ll   long long
#define pb   push_back
#define mp   make_pair
#define orz  1000000007ll
using namespace std;
int n,a[40],b[40];
ll ans;
map<ll,int> m[20];
int main(){
    scanf("%d",&n);
    for(int i=1;i<=n*2;++i){
        char c;
        scanf(" %c",&c);
        a[i]=c-96;
    }
    for(int _=(1<<n)-1;_>=0;--_){
        for(int i=0;i<n;++i)b[i+1]=(_>>i)&1;
        ll o=0,p=0;
        int cnt=0;
        for(int i=1;i<=n;++i)if(!b[i])o=(o*31ll+a[i])%orz,p=(p*47ll+a[i])%orz,++cnt;
        for(int i=n;i;--i)if(b[i])o=(o*31ll+a[i])%orz,p=(p*47ll+a[i])%orz;
        ++m[cnt][o*(orz+1)+p];
    }
    for(int _=(1<<n)-1;_>=0;--_){
        for(int i=0;i<n;++i)b[i+n+1]=(_>>i)&1;
        ll o=0;
        int cnt=0;
        for(int i=n*2;i>n;--i)if(b[i])o=(o*31ll+a[i])%orz,p=(p*47ll+a[i])%orz,++cnt;
        for(int i=n+1;i<=n*2;++i)if(!b[i])o=(o*31ll+a[i])%orz,p=(p*47ll+a[i])%orz;
        ans+=m[cnt][o*(orz+1)+p]*1ll;
    }
    cout<<ans<<endl;
	//system("pause");
	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:88:59: error: 'p' was not declared in this scope
   88 |         for(int i=n*2;i>n;--i)if(b[i])o=(o*31ll+a[i])%orz,p=(p*47ll+a[i])%orz,++cnt;
      |                                                           ^
a.cc:89:63: error: 'p' was not declared in this scope
   89 |         for(int i=n+1;i<=n*2;++i)if(!b[i])o=(o*31ll+a[i])%orz,p=(p*47ll+a[i])%orz;
      |                                                               ^
a.cc:90:31: error: 'p' was not declared in this scope
   90 |         ans+=m[cnt][o*(orz+1)+p]*1ll;
      |                               ^