Pizzeria

#include<iostream>
#include<vector>
#include<map>
#include<set>
#include<algorithm>
#include<cmath>
#include<utility>

using namespace std;

int64_t power_mod(int64_t a, int64_t k, int64_t m) {
  if(k == 0) return 1;
  int64_t res=power_mod(a, k/2, m);
  if(k%2 == 0) return res*res%m;
  return a*res%m*res%m;
}

int main(void) {
  const int64_t MOD=1000000007;
  int64_t n;
  cin >> n;
  int64_t total=0;
  int64_t p=power_mod(2,n-1,MOD);
  for(int64_t i=0;i<n;i++) {
    int64_t t;
    cin >> t;
    total+=t;
    total%=MOD;
  }
  total*=p;
  total%=MOD;
  cout << total << endl;
  return 0;
}

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