Submission #3620531

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Source Code Expand

#include "bits/stdc++.h"
#define rep(i,a,n) for(int i = a;i < n;i++)
typedef unsigned long long ull;
typedef long long ll;
using namespace std;

int main(){
	int n;
	cin >> n;
	int a[n],b[n];
	
	rep(i,0,n){
		cin >> a[i];
		b[i] = abs(n-2*i-1);
	}
	
	sort(a,a+n);
	sort(b,b+n);
	
	rep(i,0,n){
		if(a[i] != b[i]){
			cout << 0 << endl;
			return 0;
		}
	}
	
	cout << pow(2,n/2) << endl;
	
	return 0;
}

Submission Info

Judge Result