Submission #1101586

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Source Code Expand

#include <bits/stdc++.h>
#define ll long long
#define INF 999999999
#define MOD 1000000007
#define rep(i,n) for(int i=0;i<n;i++)

using namespace std;

typedef pair<int,int>P;

const int MAX_N = 100005;

int a[MAX_N];
int b[MAX_N];

int main()
{
	int n,x=0,ans=0;
	cin >> n;
	rep(i,n){
		scanf("%d",&a[i]);
		x ^= a[i];
		b[i] = a[i]^(a[i]-1);
	}
	for(int k=29;k>0;k--){
		rep(i,n){
			if(x & (1 << (k-1))){
				if(b[i] == pow(2,k)-1){
					x ^= (1<<(k-1)) - 1;
					ans++;
					break;
				}
			}else{
				break;
			}
		}
	}
	if(x==0){
		cout << ans << "\n";
	}else{
		cout << "-1\n";
	}
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:21:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]);
                    ^

Judge Result