杭电 5363 求集合的非空子集中key的数量

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  , indicating the number of test cases. For each test case:

The first line contains an integer  , 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<cstdio>
 __int64 f(__int64 a)
 {
     __int64 b=;
     __int64 t=;
     while(a)
     {
         if(a %  != )
         {
             t=(t*b)%;
         }
         b=b*b%;
         a/=;
     }
     return t;
 }
 int main()
 {
     int t;
     scanf("%d",&t);
     while(t--)
     {
         __int64 n;
         scanf("%I64d",&n);
         printf("%I64d\n",f(n-)-);
     }

 }