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

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

typedef long long ll;

const int mod = 10e9 + 7;
const int maxn = 10e5 + 5;

int a[maxn];

ll fast_mod(ll base, ll n) {
	ll res = 1;
	while (n > 0) {
		if (n & 1) res = res * base % mod;
		base = base * base % mod;
		n >>= 1;
	}
	return res % mod;
}

int main() {
	int n, num;
	cin >> n;
	memset(a, 0, sizeof(a));
	for (int i = 1; i <= n; i++) {
		cin >> num;
		a[num]++;
		if (num > n || a[num] > 2 || (n % 2 == 1 && a[0] > 1)) {
			printf("0\n"); return 0;
		}
	}
	cout << fast_mod(2, n / 2) << endl;
}

Compiler output:
a.cc:7:22: warning: overflow in conversion from 'double' to 'int' changes value from '1.0000000007e+10' to '2147483647' [-Woverflow]
    7 | const int mod = 10e9 + 7;
      |                 ~~~~~^~~
a.cc: In function 'int main()':
a.cc:25:9: error: 'memset' was not declared in this scope
   25 |         memset(a, 0, sizeof(a));
      |         ^~~~~~
a.cc:3:1: note: 'memset' is defined in header '<cstring>'; this is probably fixable by adding '#include <cstring>'
    2 | #include<iostream>
  +++ |+#include <cstring>
    3 | using namespace std;
Language: C++

#include <bits/stdc++.h>
#define int long long
using namespace std;
 
const int mod=1e9+7;
const int Max=100005;
int n,m,s;
int sum[Max];
 
inline int ksm(int a,int b)
{
	int ans=1;
	while(b)
	{
	  if(b&1) ans=(ans*a)%mod;
	  b>>=1;
	  a=(a*a)%mod;
	}
	return ans;
}
 
signed main()
{
	scanf("%d",&n);
	for(int i=1;i<=n;i++) scanf("%d",&m),sum[m]++;
	for(int i=0;i<n;i++) if(sum[i]>=3) {cout<<"0";return 0;}
	if((n&1&&sum[0]!=1)||(!(n%2)&&sum[0])) {cout<<"0";return 0;}
	cout<<ksm(2,n/2);
	return 0;
｝

Compiler output:
a.cc: In function 'int main()':
a.cc:30:1: error: '\U0000ff5d' was not declared in this scope
   30 | ｝
      | ^~
a.cc:30:3: error: expected '}' at end of input
   30 | ｝
      |   ^
a.cc:23:1: note: to match this '{'
   23 | {
      | ^
Language: C++


#include <bits/stdc++.h>
using namespace std;
#define  ll long long
const int N = 100005;
const int mod = 1e9+7;
int a[N];
int num[N];
ll qpow(ll a,ll b,ll p)
{
	ll ans=1%p;
	while(b)
	{
		if(b&1) ans=(ans*a)%p;
		b>>=1;
		a=(a*a)%p;
	}
	return ans;
}
int main()
{
    int n;
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
	{
      scanf("%d",&a[i]);  
      num[a[i]]++;
	}
	if(n%2==1)
	{
		int flag=1;
		for(int i=n-1;i>=0;i-=2)
		{
			
			if(i==0)
			{
				if(num[i]!=1)
				{
					flag=0;
					break;
				}
			}
			else
			{
				if(num[i]!=2)
				{
					flag=0;
					break;
				}
			}
		}
		if(flag==0)    printf("0\n");
		else
		{
			ll ans=qpow(2,n/2,mod)%mod;
			printf("%lld\n",ans);
		}
	}
	else
	{
		int flag=1;
		for(int i=n-1;i>=1;i-=2)
		{
			
				if(num[i]!=2)
				{
					flag=0;
					break;
				}
		}
		if(flag==0)    printf("0\n");
		else
		{
			ll ans=qpow(2,n/2,mod)%mod;
			printf("%lld\n",ans);
		}
	}
    return 0;
｝

Compiler output:
a.cc: In function 'int main()':
a.cc:79:1: error: '\U0000ff5d' was not declared in this scope
   79 | ｝
      | ^~
a.cc:79:3: error: expected '}' at end of input
   79 | ｝
      |   ^
a.cc:21:1: note: to match this '{'
   21 | {
      | ^
Language: C++


#include <bits/stdc++.h>
#define int long long
using namespace std;
 
const int mod=1e9+7;
const int Max=100005;
int n,m,s;
int sum[Max];
 
inline int ksm(int a,int b)
{
	int ans=1;
	while(b)
	{
	  if(b&1) ans=(ans*a)%mod;
	  b>>=1;
	  a=(a*a)%mod;
	}
	return ans;
}
 
signed main()
{
	scanf("%d",&n);
	for(int i=1;i<=n;i++) scanf("%d",&m),sum[m]++;
	for(int i=0;i<n;i++) if(sum[i]>=3) {cout<<"0";return 0;}
	if((n&1&&sum[0]!=1)||(!(n%2)&&sum[0])) {cout<<"0";return 0;}
	cout<<ksm(2,n/2);
	return 0;
｝

Compiler output:
a.cc: In function 'int main()':
a.cc:31:1: error: '\U0000ff5d' was not declared in this scope
   31 | ｝
      | ^~
a.cc:31:3: error: expected '}' at end of input
   31 | ｝
      |   ^
a.cc:24:1: note: to match this '{'
   24 | {
      | ^
Language: Java

import java.util.*;

class Main{
    //
    static final int DIV = 100000007L;
    static final int MAX = 2000000000;
    
    public static void main(String args[]){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] ary = new int[n];
        for(int i = 0;i < n;i++)ary[i] = sc.nextInt();
        Arrays.sort(ary);
        if(n==1&&ary[0]==0){
            System.out.println(1);
            return;
        }
        if(n%2==0){
            if(ary[0]!=1||ary[1]!=1){
                System.out.println(0);
                return;
            }
            for(int i = 0;i < n-1;i++){
                if(i%2==0&&ary[i]!=ary[i+1]){
                    System.out.println(0);
                    return;
                }
                if(i%2==1&&ary[i]!=ary[i+1]-2){
                    System.out.println(0);
                    return;
                }
            }
        }else{
            if(ary[0]!=0||ary[1]==0){
                System.out.println(0);
                return;
            }
            for(int i = 1;i < n-1;i++){
                if(i%2==1&&ary[i]!=ary[i+1]){
                    System.out.println(0);
                    return;
                }
                if(i%2==0&&ary[i]!=ary[i+1]-2){
                    System.out.println(0);
                    return;
                }
            }
        }
        long ans = 2;
        //ans=modpow(n/2);
        for(int i = 0;i < n/2-1;i++){
            ans = (2*ans)%DIV;
        }
        System.out.println(ans);
    }

    static long modpow(long n){
        long ans =1;
        long a = 2;
        while(n>0){
            if((n&1)==1)ans = ans*a % DIV;
            a = a * a % DIV;
            n >>= 1;
        }
        return ans;
    }
    
}

Compiler output:
Main.java:5: error: incompatible types: possible lossy conversion from long to int
    static final int DIV = 100000007L;
                           ^
1 error
Language: C++

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

int calc(int x){
  if(x==1) return 2;
  x--;
  int a=calc(x)%1000000007;
  a*=2;
  return a;
}

int main(){
  int n;
  cin>>n;
  vector<int> num(n);
  for(int i=0;i<n;i++){
    cin>>num[i];
  }sort(num.begin(),num.end());
  if(n==1&&num[0]==0){
    cout<<1<<endl; return 0;
  }
  if(num[0]==0){
    if(n%2==0){
      cout<<0<<endl; return 0;
    }
    for(int i=1;i<n;i++){
      if(num[i]%2==0 && num[i+1]==num[i]&&num[i-1]!=num[i]){
        i++;
        continue;
      }
      cout<<0<<endl; return 0;
    }
  }else{
    if(n%2==1){
      cout<<0<<endl; return 0;
    }
    for(int i=0;i<n;i++){
      if(num[i]%2==1 && num[i+1]==num[i] &&num[i-1]!=num[i]){
        i++;
        continue;
      }
      cout<<0<<endl; return 0;
    }int ans=calc(n/2);
  }cout<<ans<<endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:44:10: error: 'ans' was not declared in this scope; did you mean 'abs'?
   44 |   }cout<<ans<<endl;
      |          ^~~
      |          abs
Language: C++

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

int main() {
  int N;
  cin >> N;
  vector<int> A(N);
  for (int i = 0; i < N; ++i) {
    cin >> A[i];
  }
  sort(A.begin(), A.end());
  int i;
  bool flg;
  if (A[0] == 0) {
    i = 2;
    flg = true;
  } else {
    i = 1;
    flg = false;
  }
  
  ll cnt = 0;
  for (; i < N; i += 2) {
    int last = A[i - 1];
    int cur = A[i];
    if (last == cur) {
      ++cnt;
    } else {
      cnt = -1;
      break;
    }
  }
  if (cnt == -1) {
    cout << 0 << endl;
  } else {
    cout << pow(2, cnt) % (pow(10, 9) + 7) << endl;
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:37:25: error: invalid operands of types '__gnu_cxx::__promote<double>::__type' {aka 'double'} and '__gnu_cxx::__promote<double>::__type' {aka 'double'} to binary 'operator%'
   37 |     cout << pow(2, cnt) % (pow(10, 9) + 7) << endl;
      |             ~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~
      |                |                      |
      |                |                      __gnu_cxx::__promote<double>::__type {aka double}
      |                __gnu_cxx::__promote<double>::__type {aka double}
Language: C++

n=int(input())
a=list(map(int,input().split()))
a.sort()
cnt=0
ans=1
if n%2==0:
	for i in range(n//2):
		if a[2*i]==a[2*i+1]==2*i+1:
			cnt+=1
			ans=(ans*2)%(10**9+7)
		else:
			break
	if cnt==n//2:
		print(ans)
	else:
		print(0)
else:
	if a[0]!=0:
		print(0)
		exit()
	for i in range(n//2):
		if a[2*i+1]==a[2*i+2]==2*i+2:
			cnt+=1
			ans=(ans*2)%(10**9+7)
		else:
			break
	if cnt==n//2:
		print(ans)
	else:
		print(0)





Compiler output:
a.cc:1:1: error: 'n' does not name a type
    1 | n=int(input())
      | ^
Language: C++

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

#define dlog(str) cout << "====" << str << endl;
#define INF 999999999
#define MOD 1000000007
#define REP(i, n) for(int i = 0, i##_l = (n); i < i##_l; i++)
#define REP2(i, s, e) for(int i = s, i##_l = (e); i < i##_l; i++)
#define LLI long long int
#define _min(a, b) ((a < b) ? a : b)
#define _max(a, b) ((a < b) ? b : a)
#define chmax(a, b) a = _max(a, b)
#define chmin(a, b) a = _min(a, b)
#define bit(a, shift) ((a>>shift)&1))
#define pm(a) ((a) ? 1 : -1)
#define ALL(v) (v).begin(), (v).end()
#define SORT(v) sort(ALL(v))
#define RSORT(v) sort((v).rbegin(), (v).rend())
// int 2.14E±9    lli 9.2E±18    double 1.7E±380

LLI modpow(int p){
    LLI s=1;
    REP(i,p){
        s=s*2%MOD;
    }
    return s;
}

int main() {
    int N;
    cin >> N;
    vector<int> v(N);
    REP(i, N) { cin >> v[i]; }
    SORT(v);
    if(N % 2 == 0) {
        bool valid = true;
        REP(i, N / 2) {
            if(v[i * 2] != i * 2 + 1 || v[i * 2 + 1] != i * 2 + 1) {
                valid = false;
                break;
            }
        }
        if(valid) {
            cout << pow(2, N / 2);
        } else {
            cout << 0;
        }
    } else {
        bool valid = true;
        if(v[0] != 0) {
            valid = false;
        }
        REP(i, N / 2) {
            if(v[i * 2 + 1] != i * 2 + 2 || v[i * 2 + 2] != i * 2 + 2) {
                valid = false;
                break;
            }
        }
        if(valid) {
            cout << modpow(2, N / 2);
        } else {
            cout << 0;
        }
    }
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:60:27: error: too many arguments to function 'long long int modpow(int)'
   60 |             cout << modpow(2, N / 2);
      |                     ~~~~~~^~~~~~~~~~
a.cc:21:5: note: declared here
   21 | LLI modpow(int p){
      |     ^~~~~~
Language: C++

#include <bits/stdc++.h>

using namespace std;

int main(){
    int N;
    cin>>N;
    vector<int> a(N);
    int zero = 0;
    for(int i=0;i<N;i++){
        cin>>a[i];
        if(a[i]==0)
            zero++;
    }
    sort(a.begin(),a.end(),greater<int>());

    if(N%2==0&&zero>0||N%2==1&&zero>1){
        cout<<"0";
        return 0;
    }
    const int mod 1e9+7;
    int ans = 1;
    for(int i=0;i<N;i+=2){
        if(a[i]!=a[i+1]){
            cout<<"0";
            return 0;
        }
        ans+=ans*2%mod;
    }
    cout<<ans;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:21:19: error: expected initializer before numeric constant
   21 |     const int mod 1e9+7;
      |                   ^~~
a.cc:28:20: error: 'mod' was not declared in this scope; did you mean 'modf'?
   28 |         ans+=ans*2%mod;
      |                    ^~~
      |                    modf
Language: C++

#include <bits/stdc++.h>
using namespace std;
#define  ll long long
const int N = 100005;
const int mod = 1e9+7;
int a[N];
int num[N];
ll qpow(ll a,ll b,ll p)
{
	ll ans=1%p;
	while(b)
	{
		if(b&1) ans=(ans*a)%p;
		b>>=1;
		a=(a*a)%p;
	}
	return ans;
}
int main()
{
    int n;
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
	{
      scanf("%d",&a[i]);  
      num[a[i]]++;
	}
	if(n%2==1)
	{
		int flag=1;
		for(int i=n-1;i>=0;i-=2)
		{
			
			if(i==0)
			{
				if(num[i]!=1)
				{
					flag=0;
					break;
				}
			}
			else
			{
				if(num[i]!=2)
				{
					flag=0;
					break;
				}
			}
		}
		if(flag==0)    printf("0\n");
		else
		{
			ll ans=qpow(2,n/2)%mod;
			printf("%lld\n",ans);
		}
	}
	else
	{
		int flag=1;
		for(int i=n-1;i>=1;i-=2)
		{
			
				if(num[i]!=2)
				{
					flag=0;
					break;
				}
		}
		if(flag==0)    printf("0\n");
		else
		{
			ll ans=qpow(2,n/2)%mod;
			printf("%lld\n",ans);
		}
	}
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:54:36: error: too few arguments to function 'long long int qpow(long long int, long long int, long long int)'
   54 |                         ll ans=qpow(2,n/2)%mod;
      |                                ~~~~^~~~~~~
a.cc:8:4: note: declared here
    8 | ll qpow(ll a,ll b,ll p)
      |    ^~~~
a.cc:73:36: error: too few arguments to function 'long long int qpow(long long int, long long int, long long int)'
   73 |                         ll ans=qpow(2,n/2)%mod;
      |                                ~~~~^~~~~~~
a.cc:8:4: note: declared here
    8 | ll qpow(ll a,ll b,ll p)
      |    ^~~~
Language: C++

#include <iostream>
using namespace std;

typedef long long ll;

ll mod=1e9+7;

int main(){
  ll n;
  cin >> n;
  ll a[n];
  for(ll i=0;i<n;i++) cin >> a[i];
  ll check[n]={0};
  if(n%2==0){
    for(ll i=1;i<n;i++) check[i]=2;
  }
  else{
    check[0]=1;
    for(ll i=2;i<n;i++) check[i]=2;
  }
  for(ll i=0;i<n;i++){
    check[a[i]]--;
  }
  bool res=true;
  for(ll i=0;i<n;i++) if(check[i]) res=false;
  if(!res) cout << 0 << endl;
  else{
    ll ans=1;
    for(ll i=0;i<n/2;i++){
      ans=(ans*2)%mod;
    }
  }
  cout << ans << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:33:11: error: 'ans' was not declared in this scope; did you mean 'abs'?
   33 |   cout << ans << endl;
      |           ^~~
      |           abs
Language: C++

#include<iostream>
#include<vector>
#include<algorithm>
#include<stack>
#include<queue>
#include<string>
#include<cmath>
using namespace std;

#define ll long long
#define INF 99999999
#define rep(i,n) for(int i=0,temp=(int)(n);i<temp;++i) //vec.size()がnの時等の高速化
#define all(x) (x).begin(),(x).end()
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define vint vector<int>
#define vvint vector<vector<int>>

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
int gcd(int a,int b){return b?gcd(b,a%b):a;}

int n;
vint a,t;

bool judge(){
  VSORT(a);
  if(n%2!=0){
    t.push_back(0);
    rep(i,(n-1)/2){
      t.push_back((i+1)*2);
      t.push_back((i+1)*2);
    }
  }
  else{
    rep(i,n/2){
      t.push_back(2*(i+1)-1);
      t.push_back(2*(i+1)-1);
    }
  }
//  for(auto x: t) cout << x;
  return a == t;
}

int main(){
  cin >> n; a.resize(n);
  rep(i,n) cin >> a[i];
 
  ll ans=0;
  
  if(judge()){
    ans=1;
    rep(i,n/2){
      ans = ans*2 % 1e9;
    }
  }
  cout << ans << endl;

  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:54:19: error: invalid operands of types 'long long int' and 'double' to binary 'operator%'
   54 |       ans = ans*2 % 1e9;
      |             ~~~~~ ^ ~~~
      |                |    |
      |                |    double
      |                long long int
Language: C++

import sys
n = int(input())
a = list(map(int, input().split()))

a.sort()
ra = a.copy()
a = a[0::2]
ra = ra[1::2]
ra.reverse()
a = ra + a
for i in range(n):
    if a[i] != abs(n - 1 - i * 2):
        print(0)
        sys.exit(0)
print(2 ** (n // 2) % 1000000007)

Compiler output:
a.cc:1:1: error: 'import' does not name a type
    1 | import sys
      | ^~~~~~
a.cc:1:1: note: C++20 'import' only available with '-fmodules-ts'
Language: C++

#include <iostream>
#include <vector>
#include <algorithm>

#define MOD 1000000007

using namespace std;

int main() {
    ll n, ans = 1;
    cin >> n;
    vector<ll> a(n);
    for (ll i = 0; i < n; ++i) cin >> a.at(i);
    sort(a.begin(), a.end());
    for (ll i = n - 1; i >= 0; --i) {
        if (a.at(i) != (i + n % 2) / 2 * 2 + (n - 1) % 2) {
            cout << 0 << endl;
            return 0;
        }
    }
    for (ll i = 0; i < n / 2; ++i) ans = ans * 2 % MOD;
    cout << ans << endl;
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:10:5: error: 'll' was not declared in this scope
   10 |     ll n, ans = 1;
      |     ^~
a.cc:11:12: error: 'n' was not declared in this scope
   11 |     cin >> n;
      |            ^
a.cc:12:14: error: template argument 2 is invalid
   12 |     vector<ll> a(n);
      |              ^
a.cc:13:12: error: expected ';' before 'i'
   13 |     for (ll i = 0; i < n; ++i) cin >> a.at(i);
      |            ^~
      |            ;
a.cc:13:20: error: 'i' was not declared in this scope
   13 |     for (ll i = 0; i < n; ++i) cin >> a.at(i);
      |                    ^
a.cc:13:41: error: request for member 'at' in 'a', which is of non-class type 'int'
   13 |     for (ll i = 0; i < n; ++i) cin >> a.at(i);
      |                                         ^~
a.cc:14:12: error: request for member 'begin' in 'a', which is of non-class type 'int'
   14 |     sort(a.begin(), a.end());
      |            ^~~~~
a.cc:14:23: error: request for member 'end' in 'a', which is of non-class type 'int'
   14 |     sort(a.begin(), a.end());
      |                       ^~~
a.cc:15:12: error: expected ';' before 'i'
   15 |     for (ll i = n - 1; i >= 0; --i) {
      |            ^~
      |            ;
a.cc:15:24: error: 'i' was not declared in this scope
   15 |     for (ll i = n - 1; i >= 0; --i) {
      |                        ^
a.cc:16:15: error: request for member 'at' in 'a', which is of non-class type 'int'
   16 |         if (a.at(i) != (i + n % 2) / 2 * 2 + (n - 1) % 2) {
      |               ^~
a.cc:21:12: error: expected ';' before 'i'
   21 |     for (ll i = 0; i < n / 2; ++i) ans = ans * 2 % MOD;
      |            ^~
      |            ;
a.cc:21:20: error: 'i' was not declared in this scope
   21 |     for (ll i = 0; i < n / 2; ++i) ans = ans * 2 % MOD;
      |                    ^
a.cc:21:36: error: 'ans' was not declared in this scope; did you mean 'abs'?
   21 |     for (ll i = 0; i < n / 2; ++i) ans = ans * 2 % MOD;
      |                                    ^~~
      |                                    abs
a.cc:22:13: error: 'ans' was not declared in this scope; did you mean 'abs'?
   22 |     cout << ans << endl;
      |             ^~~
      |             abs
Language: C++

#include<vector>
using namespace std;

int main() {
	int n;cin>>n;
	vector<int> a(n);
	vector<int> v(10000,0);
	for(int i=0;i<n;i++){
		cin>>a[i];
		v[a[i]]++;
	}
	int flag=1;
	for(int i=0;i<n/2;i++){
		if(v[2*i+1+n%2]!=2){
			flag=0;
			break;
		}
	}
	if(n%2){
		if(v[0]!=1){
			flag=0;
		}
	}
	if(flag){
		int ans=1;
		for(int i=0;i<n/2;i++){
			ans*=2;
		}
		cout<<ans<<endl;
	}else{
		cout<<0<<endl;
	}
	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:5:15: error: 'cin' was not declared in this scope
    5 |         int n;cin>>n;
      |               ^~~
a.cc:2:1: note: 'std::cin' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
    1 | #include<vector>
  +++ |+#include <iostream>
    2 | using namespace std;
a.cc:29:17: error: 'cout' was not declared in this scope
   29 |                 cout<<ans<<endl;
      |                 ^~~~
a.cc:29:17: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:29:28: error: 'endl' was not declared in this scope
   29 |                 cout<<ans<<endl;
      |                            ^~~~
a.cc:2:1: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
    1 | #include<vector>
  +++ |+#include <ostream>
    2 | using namespace std;
a.cc:31:17: error: 'cout' was not declared in this scope
   31 |                 cout<<0<<endl;
      |                 ^~~~
a.cc:31:17: note: 'std::cout' is defined in header '<iostream>'; this is probably fixable by adding '#include <iostream>'
a.cc:31:26: error: 'endl' was not declared in this scope
   31 |                 cout<<0<<endl;
      |                          ^~~~
a.cc:31:26: note: 'std::endl' is defined in header '<ostream>'; this is probably fixable by adding '#include <ostream>'
Language: C++

n = int(input())
cnt = [0] * n
for i in input().split():
    cnt[int(i)] += 1
for i in range(1 + n % 2, n, 2):
    if cnt[i] != 2:
        print(0)
        exit(0)
print(pow(2, n // 2, int(1e9 + 7)))

Compiler output:
a.cc:1:1: error: 'n' does not name a type
    1 | n = int(input())
      | ^
Language: C++

#include<stdio.h>
#include <algorithm>
#include <boost/foreach.hpp>
using namespace std;
 
int main(){
  int i,a[100000],box[100000]={},n,b;
  long long int flag=1;
  scanf("%d",&n);
  for(i=0;i<n;i++){
    scanf("%d",&a[i]);
  }
  sort(a,a+n,greater<int>());
  b=n-1;
 
  for(i=0;i<n;i++){
    if(a[i]!=b)
      flag=0;
    if(i%2==1)
      b-=2;
  }
    for(i=0;i<n/2;i++){
      flag*=2;
      flag%=1000000007
  printf("%lld\n",flag);
}

Compiler output:
a.cc:3:10: fatal error: boost/foreach.hpp: No such file or directory
    3 | #include <boost/foreach.hpp>
      |          ^~~~~~~~~~~~~~~~~~~
compilation terminated.
Language: C++

#include <bits/stdc++.h>
#define int long long
int mpow(int k,int n,const int MOD){
    int res = 1;
    for(int i=0;i<n;i++) res=res*k%MOD;
    return res;
using namespace std;

signed main() {
  int N;
  int ans;
  cin>>N;
  int out=0;
  int k;
  std::vector<int> v(N,0);
  for(int i=0;i<N;i++){
    cin>>k;
    v[k]++;
  }
  if(N%2){
    for(int i=0;i<N;i++){
      if(i==0)if(v[i]!=1)out++;
      if(i%2)if(v[i]!=0)out++;
      if(i%2==0&&i!=0)if(v[i]!=2)out++;
    }
    if(out)cout<<0<<endl;
    else{
      ans=mpow(2,N/2,1e9+7);
      while(ans>=1000000007)ans-=1000000007;
      cout<<ans<<endl;
    }
  }
  else{
    for(int i=0;i<N;i++){
      if(i%2)if(v[i]!=2)out++;
      if(i%2==0)if(v[i]!=0)out++;
    }
    if(out)cout<<0<<endl;
    else{
      ans=mpow(2,N/2,1e9+7);
      while(ans>=1000000007)ans-=1000000007;
      cout<<ans<<endl;
    }
  }
}


Compiler output:
a.cc: In function 'long long int mpow(long long int, long long int, long long int)':
a.cc:9:12: warning: empty parentheses were disambiguated as a function declaration [-Wvexing-parse]
    9 | signed main() {
      |            ^~
a.cc:9:12: note: remove parentheses to default-initialize a variable
    9 | signed main() {
      |            ^~
      |            --
a.cc:9:12: note: or replace parentheses with braces to value-initialize a variable
a.cc:9:15: error: a function-definition is not allowed here before '{' token
    9 | signed main() {
      |               ^
a.cc:45:2: error: expected '}' at end of input
   45 | }
      |  ^
a.cc:3:36: note: to match this '{'
    3 | int mpow(int k,int n,const int MOD){
      |                                    ^
Language: C++

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

signed main() {
  int N;
  int ans;
  cin>>N;
  int out=0;
  int k;
  std::vector<int> v(N,0);
  for(int i=0;i<N;i++){
    cin>>k;
    v[k]++;
  }
  if(N%2){
    for(int i=0;i<N;i++){
      if(i==0)if(v[i]!=1)out++;
      if(i%2)if(v[i]!=0)out++;
      if(i%2==0&&i!=0)if(v[i]!=2)out++;
    }
    if(out)cout<<0<<endl;
    else{
      ans=mpow(2,N/2,1e9+7);
      while(ans>=1000000007)ans-=1000000007;
      cout<<ans<<endl;
    }
  }
  else{
    for(int i=0;i<N;i++){
      if(i%2)if(v[i]!=2)out++;
      if(i%2==0)if(v[i]!=0)out++;
    }
    if(out)cout<<0<<endl;
    else{
      ans=mpow(2,N/2,1e9+7);
      while(ans>=1000000007)ans-=1000000007;
      cout<<ans<<endl;
    }
  }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:24:11: error: 'mpow' was not declared in this scope; did you mean 'pow'?
   24 |       ans=mpow(2,N/2,1e9+7);
      |           ^~~~
      |           pow
a.cc:36:11: error: 'mpow' was not declared in this scope; did you mean 'pow'?
   36 |       ans=mpow(2,N/2,1e9+7);
      |           ^~~~
      |           pow
Language: C++

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

signed main() {
  int N;
  cin>>N;
  int out=0;
  int k;
  std::vector<int> v(N,0);
  for(int i=0;i<N;i++){
    cin>>k;
    v[k]++;
  }
  if(N%2){
    for(int i=0;i<N;i++){
      if(i==0)if(v[i]!=1)out++;
      if(i%2)if(v[i]!=0)out++;
      if(i%2==0&&i!=0)if(v[i]!=2)out++;
    }
    if(out)cout<<0<<endl;
    else cout<<pow(2,N/2)%1000000007<<endl;
  }
  else{
    for(int i=0;i<N;i++){
      if(i%2)if(v[i]!=2)out++;
      if(i%2==0)if(v[i]!=0)out++;
    }
    if(out)cout<<0<<endl;
    else cout<<pow(2,N/2)%1000000007<<endl;
  }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:22:26: error: invalid operands of types '__gnu_cxx::__promote<double>::__type' {aka 'double'} and 'int' to binary 'operator%'
   22 |     else cout<<pow(2,N/2)%1000000007<<endl;
      |                ~~~~~~~~~~^~~~~~~~~~~
      |                   |       |
      |                   |       int
      |                   __gnu_cxx::__promote<double>::__type {aka double}
a.cc:30:26: error: invalid operands of types '__gnu_cxx::__promote<double>::__type' {aka 'double'} and 'int' to binary 'operator%'
   30 |     else cout<<pow(2,N/2)%1000000007<<endl;
      |                ~~~~~~~~~~^~~~~~~~~~~
      |                   |       |
      |                   |       int
      |                   __gnu_cxx::__promote<double>::__type {aka double}
Language: C++

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

int main() {
  int N;
  cin>>N;
  int out=0;
  int k;
  std::vector<int> v(N,0);
  for(int i=0;i<N;i++){
    cin>>k;
    v[k]++;
  }
  if(N%2){
    for(int i=0;i<N;i++){
      if(i==0)if(v[i]!=1)out++;
      if(i%2)if(v[i]!=0)out++;
      if(i%2==0&&i!=0)if(v[i]!=2)out++;
    }
    if(out)cout<<0<<endl;
    else cout<<pow(2,N/2)%1000000007<<endl;
  }
  else{
    for(int i=0;i<N;i++){
      if(i%2)if(v[i]!=2)out++;
      if(i%2==0)if(v[i]!=0)out++;
    }
    if(out)cout<<0<<endl;
    else cout<<pow(2,N/2)%1000000007<<endl;
  }
}


Compiler output:
a.cc: In function 'int main()':
a.cc:21:26: error: invalid operands of types '__gnu_cxx::__promote<double>::__type' {aka 'double'} and 'int' to binary 'operator%'
   21 |     else cout<<pow(2,N/2)%1000000007<<endl;
      |                ~~~~~~~~~~^~~~~~~~~~~
      |                   |       |
      |                   |       int
      |                   __gnu_cxx::__promote<double>::__type {aka double}
a.cc:29:26: error: invalid operands of types '__gnu_cxx::__promote<double>::__type' {aka 'double'} and 'int' to binary 'operator%'
   29 |     else cout<<pow(2,N/2)%1000000007<<endl;
      |                ~~~~~~~~~~^~~~~~~~~~~
      |                   |       |
      |                   |       int
      |                   __gnu_cxx::__promote<double>::__type {aka double}
Language: C++

using System;
using System.Linq;
using System.Diagnostics;
using System.Collections.Generic;
using static System.Math;

class P
{
    static void Main()
    {
        int n = int.Parse(Console.ReadLine());
        int[] a = Console.ReadLine().Split().Select(int.Parse).OrderByDescending(x => x).ToArray();
        for (int i = 0; i < a.Length; i++)
        {
            if (a[i] != (n - 1) - ((i / 2) * 2))
            {
                Console.WriteLine(0);
                return;
            }
        }

        Console.WriteLine(power(2, n / 2));
    }

    
    static int power(int n, int m)
    {
        const int mod = 1000000007;
        long pow = n;
        long res = 1;
        while (m > 0)
        {
            if ((m & 1) == 1) res = (res * pow) % mod;
            pow = (pow * pow) % mod;
            m >>= 1;
        }
        return (int)res;
    }
}

Compiler output:
a.cc:1:7: error: expected nested-name-specifier before 'System'
    1 | using System;
      |       ^~~~~~
a.cc:2:7: error: expected nested-name-specifier before 'System'
    2 | using System.Linq;
      |       ^~~~~~
a.cc:3:7: error: expected nested-name-specifier before 'System'
    3 | using System.Diagnostics;
      |       ^~~~~~
a.cc:4:7: error: expected nested-name-specifier before 'System'
    4 | using System.Collections.Generic;
      |       ^~~~~~
a.cc:5:7: error: expected nested-name-specifier before 'static'
    5 | using static System.Math;
      |       ^~~~~~
a.cc:39:2: error: expected ';' after class definition
   39 | }
      |  ^
      |  ;
a.cc: In static member function 'static void P::Main()':
a.cc:11:17: error: expected primary-expression before 'int'
   11 |         int n = int.Parse(Console.ReadLine());
      |                 ^~~
a.cc:12:12: error: structured binding declaration cannot have type 'int'
   12 |         int[] a = Console.ReadLine().Split().Select(int.Parse).OrderByDescending(x => x).ToArray();
      |            ^~
a.cc:12:12: note: type must be cv-qualified 'auto' or reference to cv-qualified 'auto'
a.cc:12:12: error: empty structured binding declaration
a.cc:12:15: error: expected initializer before 'a'
   12 |         int[] a = Console.ReadLine().Split().Select(int.Parse).OrderByDescending(x => x).ToArray();
      |               ^
a.cc:13:29: error: 'a' was not declared in this scope
   13 |         for (int i = 0; i < a.Length; i++)
      |                             ^
a.cc:17:17: error: 'Console' was not declared in this scope
   17 |                 Console.WriteLine(0);
      |                 ^~~~~~~
a.cc:22:9: error: 'Console' was not declared in this scope
   22 |         Console.WriteLine(power(2, n / 2));
      |         ^~~~~~~
Language: C++

#include <iostream>
#include <algorithm>
#include <cmath>
using namespace std;
long a,cnt[100000];
int main(void){
    cin>>q;
    for(long i=-1;++i-q;){
        cin>>a;
        ++cnt[a];
    }
    for(long i=-1;++i-q;){
        if(cnt[i]=!((i+a)&1)*2-!i&&a&1)break;
    }
    if(i==q){
        cnt[0]=1;
        for(long i=-1;++i-(a/2);)cnt[0]=(cnt[0]*2)%1000000007;
        cout<<cnt[0]<<endl;
    }
    else cout<<0<<endl;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:10: error: 'q' was not declared in this scope
    7 |     cin>>q;
      |          ^
a.cc:15:8: error: 'i' was not declared in this scope
   15 |     if(i==q){
      |        ^
Language: C++

#include<iostream>
#include<bits/stdc++.h>
#include<cmath>
using namespace std;
#define ll long long int
ll num[500000],cnt[500000]= {0};
long long int bigmod(long long int a,long long int b,long long int p)
{
    long long int val,ret;
    //printf("b=%lld\n",b);


    if(b==0)
    {
        return 1;
    }
    if(b%2==1)
    {
        ret= ((a*bigmod(a,b-1,p))%p);
        //printf("ret1=%lld\n",ret);

    }
    else
    {
        val=bigmod(a,b/2,p);
        ret= ((val *val)%p);
        //printf("ret2=%lld\n",ret);


    }
    return ret;
}

int main()
{

    ll n,i,j,k,flag=1,cnt1=1,res,res1;
    scanf("%lld",&n);
    for(i=0; i<n; i++)
    {
        scanf("%lld",&num[i]);
    }
    if(n%2==0)
    {
        for(i=1; i<n; i+=2)
            cnt[i]=2;
    }
    else
    {
        cnt[0]=1;
        for(i=2; i<n; i+=2)
            cnt[i]=2;

    }
    sort(num,num+n);
    flag=1;

    if(n%2==0)
    {

        for(i=1; i<n; i++)
        {
            if(num[i]==num[i-1])
            {
                cnt1++;
                if(cnt[num[i]]!=cnt1)
                {
                    flag=0;
                    break;
                }

            }
            else(cnt1=1;)

        }
    }
    else
    {


        for(i=1; i<n; i++)
        {
            if(num[0]!=0)
            {
                flag=0;
                //printf("f1 %lld\n",flag);
                break;

            }



            if(num[i]==0)
            {
                flag=0;
                //printf("f2 %lld\n",flag);
                break;
            }
            if(num[i]==num[i-1])
            {
                cnt1++;
                //printf("cnt %lld\n",cnt1);
                 //printf("num %lld\n",num[i]);

                //printf("arr %lld\n",cnt[num[i]]);
                if(cnt[num[i]]!=cnt1)
                {
                    flag=0;
                    //printf("f3 %lld\n",flag);
                    break;
                }

            }
            else{cnt1=1;}

        }


    }


    if(flag==1)
    {


        k=n/2;
        res=bigmod(2,k,1000000007);
        printf("%lld\n",res);

    }
    else
    {
        printf("0\n");
    }



    return 0;
}




Compiler output:
a.cc: In function 'int main()':
a.cc:73:24: error: expected ')' before ';' token
   73 |             else(cnt1=1;)
      |                 ~      ^
      |                        )
a.cc:73:25: error: expected primary-expression before ')' token
   73 |             else(cnt1=1;)
      |                         ^
Language: C++

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
const int mod=1e9+7;
int a[100001];
int n;
int pow1(int a,int n)
{
	if(n==0) return 1;
	int x=pow1(a,n/2);
	long long ans=(long long)x*x%mod;
	if(n%2==1) ans=ans*a%mod;
	return ans;
}
bool check()
{
	sort(a+1,a+n+1);
	if(a[1]==0)
	for(int i=2;i<=n;)
	{
		if(a[i]!=a[i+1])
		return false;
		i+=2;
	}
	else
	{
		for(int i=1;i<=n;)
		if(a[i]!=a[i+1])
		return false;
		i+=2;
	}
	return true;
}
int main()
{
	scanf("%d",&n);
	int flag=0;
	for(int i=1;i<=n;i++)
	{
		scanf("%d",&a[i]);
		if(a[i]==0)
		flag++;
	}
	if(flag==2||n%2==0&&flag>0||!check())
	printf("0\n");
	else 
	{
		if(flag==1)
		{
			n=n-1;
			n/=2;
		}
		else
		n/=2;
		int ans=pow1(2,n);
		printf("%d\n",ans);
	}
	return 0;
}

Compiler output:
a.cc: In function 'bool check()':
a.cc:31:17: error: 'i' was not declared in this scope
   31 |                 i+=2;
      |                 ^
Language: C

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

int compare_int(const void *a, const void *b)
{
    return *(int*)a - *(int*)b;
}

int main(void)
{int N,A,M,B,X,C,x,i,a,b,c,l,r,g,flag,m,tmp;
	long long int sum;
	scanf("%d",&N);
	sum=1;
	flag=0;
	int A[100000];
	for(i=0;i<N;i++){
		scanf("%d",A[i]);}
		qsort(A, N, sizeof(int), compare_int);
if(N%2==0){
	for(i=0;2*i+1<N;i++){
		if(A[2*i]!=2*i+1||A[2*i+1]!=2*i+1){
			flag=1;
			break;}}
			if(flag==0){
			
			x=N/2;
			for(a=1;a<=x;a++){
			sum*=2;
			if(sum>=1000000007){
				sum%=1000000007;}}}
	}
	else{
	for(i=0;2*i+1<N-1;i++){
		if(A[2*i]!=2*i||A[2*i+1]!=2*i+2||A[N-1]!=N-1){
			flag=1;
			break;}}
			if(flag==0){
			x=N/2;
			for(a=1;a<=x;a++){
			sum*=2;
			if(sum>=1000000007){
				sum%=1000000007;}}}}
	
	if(flag==0){
	printf("%lld",sum);}
	else
	printf("0");
			


	return 0;
}


Compiler output:
main.c: In function 'main':
main.c:15:13: error: conflicting types for 'A'; have 'int[100000]'
   15 |         int A[100000];
      |             ^
main.c:10:8: note: previous declaration of 'A' with type 'int'
   10 | {int N,A,M,B,X,C,x,i,a,b,c,l,r,g,flag,m,tmp;
      |        ^
Language: C++

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

int main(){
	long long int n;
	cin>>n;
	vector<long long int> a(n);
	for(int i=0;i<n;i++){
		int b;
		cin>>b;
		a[b]++;
	}
	
	int f=1;
	if(n%2==0){
		for(int i=1;i<n;i+=2){
			if(a[i]!=2)f=0;
		}
	}else{
		for(int i=2;i<n;i+=2){
			if(a[i]!=2)f=0;
		}
		if(a[0]!=1)f=0;
	}
	
	if(f==0){
		cout<<0<<endl;
	}else{
		long long int ans=1;
		for(int i=0;i<n/2;i++){
			ans*=2;
			ans%=1e9+7;
		}
		cout<<ans<<endl;
	}
}

Compiler output:
a.cc: In function 'int main()':
a.cc:32:28: error: invalid operands of types 'long long int' and 'double' to binary 'operator%'
   32 |                         ans%=1e9+7;
      |                         ~~~^~~~~~~
a.cc:32:28: note:   in evaluation of 'operator%=(long long int, double)'
Language: C++

// g++ macro.cpp -std=c++14
#include <bits/stdc++.h> //STL include
typedef long long ll;// long long int
const ll INF = 10000000000;//INFinity
using namespace std;//namespace

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}//transform
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

//#define int long long // yabai

#define dump(x)  cout << #x << " = " << (x) << endl;// debug cout

#define FOR(i,a,b) for(int i=(a);i<(b);++i)// for macro
#define REP(i,n) for(int i=0;i<(n);++i)
#define REPR(i,n) for(int i=n;i>=0;i--)

#define ALL(obj) (obj).begin(),(obj).end()// iterator

#define pb(a) push_back(a)//push_back
#define mp make_pair// make_pair


int main(){

    int n;
    cin>>n;
    map<int,int> map_;
    REP(i,n){
        int t;
        cin>>t;
        map_[t]++;
    }
    ll x=-1;
    for(auto t:map_)if(t.first%2==n%2||(t.first==0&&t.second!=1)||(t.first&&t.second!=2))x=0;
    if(x!=0)x=(n%2==1?pow(2,map_.size()-1)%(pow(10,9)+7):pow(2,map_.size())%(pow(10,9)+7));
    cout<<x%((ll)pow(10,9)+7)<<endl;
    

    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:36:43: error: invalid operands of types '__gnu_cxx::__promote<double>::__type' {aka 'double'} and '__gnu_cxx::__promote<double>::__type' {aka 'double'} to binary 'operator%'
   36 |     if(x!=0)x=(n%2==1?pow(2,map_.size()-1)%(pow(10,9)+7):pow(2,map_.size())%(pow(10,9)+7));
      |                       ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
      |                          |                           |
      |                          |                           __gnu_cxx::__promote<double>::__type {aka double}
      |                          __gnu_cxx::__promote<double>::__type {aka double}
a.cc:36:76: error: invalid operands of types '__gnu_cxx::__promote<double>::__type' {aka 'double'} and '__gnu_cxx::__promote<double>::__type' {aka 'double'} to binary 'operator%'
   36 |     if(x!=0)x=(n%2==1?pow(2,map_.size()-1)%(pow(10,9)+7):pow(2,map_.size())%(pow(10,9)+7));
      |                                                          ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
      |                                                             |                         |
      |                                                             |                         __gnu_cxx::__promote<double>::__type {aka double}
      |                                                             __gnu_cxx::__promote<double>::__type {aka double}
Language: C++

// g++ macro.cpp -std=c++14
#include <bits/stdc++.h> //STL include
typedef long long ll;// long long int
const ll INF = 10000000000;//INFinity
using namespace std;//namespace

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}//transform
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

//#define int long long // yabai

#define dump(x)  cout << #x << " = " << (x) << endl;// debug cout

#define FOR(i,a,b) for(int i=(a);i<(b);++i)// for macro
#define REP(i,n) for(int i=0;i<(n);++i)
#define REPR(i,n) for(int i=n;i>=0;i--)

#define ALL(obj) (obj).begin(),(obj).end()// iterator

#define pb(a) push_back(a)//push_back
#define mp make_pair// make_pair


int main(){

    int n;
    cin>>n;
    map<int,int> map_;
    REP(i,n){
        int t;
        cin>>t;
        map_[t]++;
    }
    ll x=-1;
    for(auto t:map_)if(t.first%2==n%2||(t.first==0&&t.second!=1)||(t.first&&t.second!=2))x=0;
    if(x!=0)x=(n%2==1?pow(2,map_.size()-1):pow(2,map_.size()));
    cout<<x%(pow(10,9)+7)<<endl;
    

    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:37:12: error: invalid operands of types 'll' {aka 'long long int'} and '__gnu_cxx::__promote<double>::__type' {aka 'double'} to binary 'operator%'
   37 |     cout<<x%(pow(10,9)+7)<<endl;
      |           ~^~~~~~~~~~~~~~
      |           |           |
      |           |           __gnu_cxx::__promote<double>::__type {aka double}
      |           ll {aka long long int}
Language: C++

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

int main(int argc, char const *argv[]) {
  int n;
  cin >> n;
  int a[n];
  for (int i = 0; i < n; i++)
    cin >> a[i];

  int cnt[n];
  memset(cnt, 0, sizeof(cnt));
  if (n % 2 != 0) {
    for (int i = 0; i < n; i++) {
      cnt[a[i]]++;
    }
    if (cnt[0] == 1) {
      bool flag = true;
      for (int i = 2; i < n; i += 2) {
        if (cnt[i] != 2) {
          flag = false;
        }
      }
      if (flag) {
        cout << pow(2.0, (n - 1) / 2) << endl;
      } else {
        cout << 0 << endl;
      }
    } else {
      cout << 0 << endl;
    }
  } else {
    for (int i = 0; i < n; i++) {
      cnt[a[i]]++;
    }
    bool flag = true;
    for (int i = 1; i < n; i += 2) {
      if (cnt[i] != 2) {
        flag = false;
      }
    }
    if (flag) {
      cout << pow(2.0, n / 2) << endl;
    } else {
      cout << 0 << endl;
    }
  }
  return 0;
}

Compiler output:
a.cc: In function 'int main(int, const char**)':
a.cc:14:3: error: 'memset' was not declared in this scope
   14 |   memset(cnt, 0, sizeof(cnt));
      |   ^~~~~~
a.cc:4:1: note: 'memset' is defined in header '<cstring>'; this is probably fixable by adding '#include <cstring>'
    3 | #include <iostream>
  +++ |+#include <cstring>
    4 | using namespace std;
Language: C++

#include<bits/stdc++.h>
using namespace std;
const int MAXN=100010;
int x[MAXN],c[2*MAXN];
int main(){
	int n;
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>x[i];
		c[x[i]]++;
	}
	bool nemoguce=false;
	if(n%2==0){
		for(int i=1;i<=n;i+=2){
			if(c[i]!=2){
				nemoguce=true;
				break;
			}
		}	
	}
	if(n%2==1){
		if(c[0]>1)	nemoguce=true;
		if(!nemoguce){
			for(int i=2;i<=n;i+=2){
				if(c[i]!=2){
					nemoguce=true;
					break;
				}
			}	
		}
	}
	long long int r;
	if(nemoguce) r=0;
	else{
		r=1;
		for(int i=0;i<n/2;i++){
			r*=2;
			r%=pow(10,9)+7;
		}
	}
	cout<<r;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:38:26: error: invalid operands of types 'long long int' and '__gnu_cxx::__promote<double>::__type' {aka 'double'} to binary 'operator%'
   38 |                         r%=pow(10,9)+7;
      |                         ~^~~~~~~~~~~~~
a.cc:38:26: note:   in evaluation of 'operator%=(long long int, __gnu_cxx::__promote<double>::__type {aka double})'
Language: C++

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <functional>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <utility>
#include <sstream>
#include <complex>
#include <fstream>
#include <bitset>

using namespace std;

#define FOR(i,a,b) for(long long i=(a);i<(b);i++)
#define REP(i,N) for(long long i=0;i<(N);i++)
#define ALL(s) (s).begin(),(s).end()
#define fi first
#define se second

typedef long long ll;
typedef pair<ll, ll> P;
typedef vector<ll> V;

#define PI acos(-1.0)
#define EPS 1e-10
const ll INF = 1e9 + 7;
const ll MOD = 1e9 + 7;

ll n;
ll a[100100];

ll sq(ll num){
	return num*num;
}

ll mod_pow(ll num, ll k){
	if (k == 0)return 1;
	if (k == 1)return num;
	ll res = sq(mod_pow(num, k / 2));
	res %= INF;
	if (k % 2 == 1){
		res *= num;
		res %= INF;
	}
	return res;
}

int main(){
	cin >> n;
	REP(i, n)cin >> a[i];
	sort(a, a + n);
	//bool f = 1;
	//int cnt;
	//if (n % 2 == 0)cnt = 1;
	//else cnt = 0;
	//REP(i, n){
	//	if (cnt != a[i])f = 0;
	//	if (n % 2 == 0){
	//		if (i % 2 == 1)cnt += 2;
	//	}
	//	else{
	//		if (i % 2 == 0)cnt += 2;
	//	}
	//}
	ll ans = mod_pow(2, n / 2);
	if (f)cout << ans << endl;
	else cout << 0 << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:73:13: error: 'f' was not declared in this scope
   73 |         if (f)cout << ans << endl;
      |             ^
Language: C++

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

int main(){
long long int n;
cin >> n;
vector <int> a,b ;
for(int i =0; i < n; i++){
int tmp;
cin >> tmp;
b.push_back (tmp);
a.push_back(abs (n-2*i-1));
}
sort(a.begin(), a.end ());
bool flag = true;

for(int i = 0; i <n; i++){
if(a[i]!=b[i]) flag = false;
}
if(!flag) ans=0;

if(n%2!=0) n--;
n/=2;
long long int ans = 1;
for(int i = 0; i <n; i++){
ans *= 2;
ans %= 1000000007;
}
cout << ans << endl ;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:20:11: error: 'ans' was not declared in this scope; did you mean 'abs'?
   20 | if(!flag) ans=0;
      |           ^~~
      |           abs
Language: C++

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

int main(){
long long int n;
cin >> n;
if(n%2!=0) n--;
n/=2;
long long int ans = 1;
for(int i = 0; i <n i++;){
ans *= 2;
ans %= 1000000009;
}
cout << ans << endl ;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:10:20: error: expected ';' before 'i'
   10 | for(int i = 0; i <n i++;){
      |                    ^~
      |                    ;
a.cc:10:24: error: expected ')' before ';' token
   10 | for(int i = 0; i <n i++;){
      |    ~                   ^
      |                        )
a.cc:10:25: error: expected primary-expression before ')' token
   10 | for(int i = 0; i <n i++;){
      |                         ^
Language: C++

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

int main(){
long long int n;
cin >> n;
if(n%2!=0) n--;
n/=2;
long long int ans = 1;
for(i = 0; i <n i++;){
ans *= 2;
ans %= 1000000009;
}
cout << ans << endl ;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:10:5: error: 'i' was not declared in this scope
   10 | for(i = 0; i <n i++;){
      |     ^
a.cc:10:16: error: expected ';' before 'i'
   10 | for(i = 0; i <n i++;){
      |                ^~
      |                ;
a.cc:10:20: error: expected ')' before ';' token
   10 | for(i = 0; i <n i++;){
      |    ~               ^
      |                    )
a.cc:10:21: error: expected primary-expression before ')' token
   10 | for(i = 0; i <n i++;){
      |                     ^
Language: C++

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

int main(){
long long int n;
cin >> n;
if(n%2!=0) n--;
n/=2;
ans = 1;
for(i = 0; i <n i++;){
ans *= 2;
ans %= 1000000009;
}
cout << ans << endl ;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:1: error: 'ans' was not declared in this scope; did you mean 'abs'?
    9 | ans = 1;
      | ^~~
      | abs
a.cc:10:5: error: 'i' was not declared in this scope
   10 | for(i = 0; i <n i++;){
      |     ^
a.cc:10:16: error: expected ';' before 'i'
   10 | for(i = 0; i <n i++;){
      |                ^~
      |                ;
a.cc:10:20: error: expected ')' before ';' token
   10 | for(i = 0; i <n i++;){
      |    ~               ^
      |                    )
a.cc:10:21: error: expected primary-expression before ')' token
   10 | for(i = 0; i <n i++;){
      |                     ^
Language: C++

#include <iostream>
#include <vector>
using namespace std;
typedef long long lli;
lli n;
vector<lli> a;

int error(){
    cout << 0 << endl;
    return 0;
}
int main(int argc, char const *argv[]) {
    cin >> n;
    a = vector<lli> (n);
    for(lli i = 0;i < n;i++) cin >> a[i];
    sort(a.begin(),a.end());
    if(n%2 == 0){
        for(lli i = 1,j = 0;j < n;i+=2){
            if(a[j++] != i) return error();
            if(a[j++] != i) return error();
        }
    }else{
        if(a[0] != 0) return error();
        for(lli i = 2,j = 1;j < n;i += 2){
            if(a[j++] != i) return error();
            if(a[j++] != i) return error();
        }
    }
    cout << (n/2)*(n/2) << endl;
    return 0;
}


Compiler output:
a.cc: In function 'int main(int, const char**)':
a.cc:16:5: error: 'sort' was not declared in this scope; did you mean 'short'?
   16 |     sort(a.begin(),a.end());
      |     ^~~~
      |     short
Language: C++

#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=a;i<b;i++)
#define REP(i,b) FOR(i,0,b)
#define INF 1e9

int main(){
  int i = 0,N,A[N-1];

  cin>>N;

  while (i < N) {
    cin>>A[i];
    i++;
  }

  if (N%2 = 0) {
    cout<<pow(2,N-1);
  } else {
    cout<<pow(2,(N-1)/2);
  }

  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:17:8: error: lvalue required as left operand of assignment
   17 |   if (N%2 = 0) {
      |       ~^~
Language: C++

#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=a;i<b;i++)
#define REP(i,b) FOR(i,0,b)
#define INF 1e9

int main(){
  int i = 0,N,A[N-1];

  cin>>N;

  while (i < N) {
    cin>>A[i];
    i++;
  }

  if (N%2 = 0) {
    cout<<2**(N/2);
  } else {
    cout<<2**((N-1)/2);
  }

  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:17:8: error: lvalue required as left operand of assignment
   17 |   if (N%2 = 0) {
      |       ~^~
a.cc:18:13: error: invalid type argument of unary '*' (have 'int')
   18 |     cout<<2**(N/2);
      |             ^~~~~~
a.cc:20:13: error: invalid type argument of unary '*' (have 'int')
   20 |     cout<<2**((N-1)/2);
      |             ^~~~~~~~~~