Pizzeria

#include <bits/stdc++.h>
#define F first
#define S second
using namespace std;
typedef long long ll;
typedef long double ld;

const ll mod=1e9+7;

ll pot(ll a, ll p){
	if (p==0) return 1;
	if (p==2) return (a*a)%mod;
	if (p%2==1) return (a*pot(a, p-1))%mod;
	ll t=pot(a, p/2);
	return (t*t)%mod;
}

int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int n;
	cin>>n;
	ll s=0;
	for (int i=0;i<n;i++){
		ll a;
		cin>>a;
		s+=a*pot(2, n-1);
		s%=mod;
	}
	cout<<s<<endl;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED