1582B - Luntik and Subsequences(900)

#include<bits/stdc++.h>
using namespace std;
int main(){
    long long n,m,a[1000],ans1,ans2,k;
    scanf("%d",&n);
    for(int i=1;i<=n;i++){
        scanf("%lld",&m);
        memset(a,0,sizeof(a));
        ans1=0;ans2=0;k=0;
        for(int i=1;i<=m;i++){
            scanf("%lld",&a[i]);
            if(a[i]==1){
                ans1++;
            }
            if(a[i]==0){
                ans2++;
            }
        } 
        if(ans1){
            k=ans1*pow(2,ans2);
        }
        printf("%lld\n",k);
        
    }
    return 0;
}