hdu 5363Key Set

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=5363

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

一看数据就是快速幂，一开始用int错了，索性全改为long long

 #include <iostream>
 #include <cmath>
 using namespace std;

 long long f(long long a)
 {
     long long temp=;
     long long ans=;
     while (a)
     {
           if (a%!=)
           ans*=temp;

           ans=ans%;
           temp=temp*temp;
           temp=temp%;
           a/=;
     }
     return ans;
 }
 int main()
 {
      long long n,m;
      cin>>n;
      while (n--)
      {
            cin>>m;
            cout <<f(m-)-<<endl;
      }
      return ;
 }