Pizzeria

#include <iostream>
using namespace std;
int n;

const long long M=1000000007;



int main(){
  ios_base::sync_with_stdio(0); cin.tie(0);
  
  cin >> n;
  
  long long k=1;
  for (int i=1; i<n; ++i){
    k*=2;
    k%=M;
  }
  long long ans=0;
  long long t;
  for (int i=0; i<n; ++i){
    cin >> t;
    ans=(ans+t*k%M)%M;
  }
  cout << ans << 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