多校6 1011 Key Set

Key Set

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)
Total Submission(s): 1476    Accepted Submission(s): 726

Problem Description

soda has a set S with n integers {1,2,…,n}. A set is called key set if the sum of integers in the set is an even number. He wants to know how many nonempty subsets of S are key set.

 

Input

There are multiple test cases. The first line of input contains an integer T (1≤T≤105), indicating the number of test cases. For each test case:

The first line contains an integer n (1≤n≤109), the number of integers in the set.

 

Output

For each test case, output the number of key sets modulo 1000000007.

 

Sample Input

4 1 2 3 4

 

Sample Output

0 1 3 7

#include <stdio.h>
#include <string.h>
using namespace std;
long long mod=1000000007;

long long pow_mod(long long x, long long n)    {
    long long res = 1;
    while (n)    {
        if (n & 1)    res = res * x % mod;
        x = x * x % mod;
        n >>= 1;
    }
    return res;
}

int main()
{
    int T;
    long long n;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%I64d",&n);
        printf ("%I64d
", pow_mod (2, n - 1) - 1);
    }
    return 0;
}