http://codevs.cn/problem/2115/
1 // <2115.cpp> - Sun Oct 9 12:58:23 2016 2 // This file is made by YJinpeng，created by XuYike's black technology automatically. 3 // Copyright (C) 2016 ChangJun High School, Inc. 4 // I don't know what this program is. 5 6 #include <iostream> 7 #include <cstdio> 8 #define LL long long 9 using namespace std; 10 int quick_pow(int a,int b,int p){ 11 int w=1; 12 while(b){ 13 if(b&1)w=(w*a)%p; 14 b>>=1;a=(a*a)%p; 15 } 16 return w; 17 } 18 int main() 19 { 20 freopen("2115.in","r",stdin); 21 freopen("2115.out","w",stdout); 22 int n;scanf("%d",&n); 23 int ans=(quick_pow(2,n/2,10000)-1)*(quick_pow(2,(n-1)/2,10000)-1); 24 ans%=10000;printf((n>=15?"%.4d":"%d"),ans); 25 return 0; 26 }