快速幂 --- CSU 1556: Jerry's trouble

Jerry's trouble

Problem's Link:   http://acm.csu.edu.cn/OnlineJudge/problem.php?id=1556

---

Mean:

略。

analyse:

水题，直接快速幂。

Time complexity: O(n)

Source code: 

//  Memory   Time
//  1347K     0MS
//   by : crazyacking
//   2015-03-29-19.18
#include<map>
#include<queue>
#include<stack>
#include<cmath>
#include<cstdio>
#include<vector>
#include<string>
#include<cstdlib>
#include<cstring>
#include<climits>
#include<iostream>
#include<algorithm>
#define MAXN 1000010
#define LL long long
using namespace std;
const LL MOD=1e9+; 

LL quick_pow(LL a,LL b,LL m)
{
        LL ans=;
        while(b)
        {
                if(b&)
                {
                        ans*=a;
                        ans%=m;
                }
                a*=a;
                a%=m;
                b/=;
        }
        return ans%m;
} 

int main()
{
        ios_base::sync_with_stdio(false);
        cin.tie();
//      freopen("C:\\Users\\Devin\\Desktop\\cin.cpp","r",stdin);
//      freopen("C:\\Users\\Devin\\Desktop\\cout.cpp","w",stdout);
        LL n,m;
        while(cin>>n>>m)
        {
                LL sum=;
                for(int i=;i<=n;++i)
                {
                        sum+=quick_pow(i,m,MOD);
                        sum%=MOD;
                }
                cout<<sum%MOD<<endl;
        }
        return ;
}
/* 

*/

/**************************************************************
    Problem: 1556
    User: crazyacking
    Language: C++
    Result: Accepted
    Time:2704 ms
    Memory:1476 kb
****************************************************************/