杭电-5363 Key Set

 

Key Set

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)

Total Submission(s): 1781    Accepted Submission(s): 937

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
  

 

Author

zimpha@zju

 

Source

2015 Multi-University Training Contest 6

 

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wange2014

#include<stdio.h>
int quictpow(__int64 m)
{
	int ans=1;
	__int64 base=2;
	while(m>0)
	{
		if(m%2==1)
		{
			ans=(ans*base)%1000000007;
		}
		base=(base*base)%1000000007;
		m=m/2;
	}
	return ans;
}
int main()
{
	int t;
	__int64 n;
	scanf("%d",&t);
	while(t--)
	{
		scanf("%I64d",&n);
		printf("%d\n",quictpow(n-1)-1);
	}
	return 0;
}