HDU 5363 Key Set (Fast power modulo)

Key Set

Problem Descriptionsoda have a set $S $ with $n $ integers $\{1, 2, \dots, n\}$. A set is called key set if the sum of integers in the set are an even number. He wants to know how many nonempty subsets of $S $ is key set.

Inputthere is multiple test cases. The first line of input contains an integer $T $ $ (1 \le T \le 10^5) $, indicating the number of test cases. For each test case:

The first line contains a integer $n $ $ (1 \le n \le 10^9) $, the number of integers in the set.

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

Sample Input4 1 23 4

Sample Output0 1 3 7

1#include <cstdio>2 using namespacestd;3 4 Const Long Long intMod=1000000007;5 6 voidQuickmod (intAintBLong LongN)7 {8     Long Longres=1, temp=a%N;9      while(b)Ten     { One         if(b&1) res= (res*temp)%N; Atemp= (temp*temp)%N; -b>>=1; -     } theprintf"%lld\n", res-1); - } -  - intMain () + { -     intT,n; +scanf"%d",&t); A      while(t--) at     { -scanf"%d",&n); -Quickmod (2, N-1, MoD); -     } -     return 0; -}

HDU 5363 Key Set (Fast power modulo)