2015 multiply 6 1011

Key Set
Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others) Total Submission(s): 207    Accepted Submission(s): 135
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
   
   
   
   

 
Source
2015 Multi-University Training Contest 6
 
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//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<cstdio>
#include<cmath>
#include<stdlib.h>
#include<map>
#include<set>
#include<time.h>
#include<vector>
#include<queue>
#include<string>
#include<string.h>
#include<iostream>
#include<algorithm>
using namespace std;
#define eps 1e-8
#define INF 0x3f3f3f3f
#define LL long long
#define max(a,b) ((a)>(b)?(a):(b))
#define min(a,b) ((a)<(b)?(a):(b))
typedef pair<int , int> P;
#define mod 1000000007

int main()
{
    int T;
    scanf("%d", &T);
    while(T--)
    {
        int n;
        scanf("%d", &n);
        int ans = 1;
        int a = 2;
        n--;
        while(n)
        {
            if(n & 1) ans = ((LL)ans * a) % mod;
            a = ((LL)a * a) % mod;
            n >>= 1;
        }
        ans--;
        printf("%d
", ans % mod);
    }
    return 0;
}