Pizzeria

#include <bits/stdc++.h>

#define i64 long long
#define u64 unsigned long long
#define i32 int
#define u32 unsigned int

#define pii pair<int, int>
#define pll pair<long long, long long>

#define defmod 1000000007
using namespace std;


int n;
i64 t[101010];

long long re = 0;
unordered_set<int> d;
void hae(int b){
	if(d.count(b))
		return;
	d.insert(b);
	for(int i = 0; i < n; i++){
		if(b&(1<<i)){
			re+=t[i];
			re%=defmod;

		}
		else
			hae(b|(1<<i));
	}

}
int main(){
	cin.sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n;
	for(int i = 0; i < n; i++)
		cin >> t[i];

	//hae(0);
	//cout << re << endl;
	i64 k2 = 1;
	for(int i = 1; i < n; i++){
		k2*=2;
		k2%=defmod;
	}
	i64 re2 = 0;
	for(int i = 0; i < n; i++){
		re2+=t[i]*k2;
		re2%=defmod;
	}
	cout << re2 << 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