杭电 oj1097

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

long long int quickpow(long long int m,int n,int k)
{
   long long int ans=1;
    while(n>0)
    {
        if(n&1)
            ans=(ans*m)%k;
        n=n>>1;
        m=(m*m)%k;
    }
    return ans;
}

int main()
{

    long long int a;
    int b;
    while(cin>>a>>b)
    {
        cout<<quickpow(a,b,10)<<endl;

    }
    return 0;
}

　　亲测用快速幂模板~如果ans和m不用longlong会爆int~，当然可以不这样~

代码如下~

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

int quickpow(int m,int n,int k)
{
    m=m%k;
   int ans=1;
    while(n>0)
    {
        if(n&1)
            ans=(ans*m)%k;
        n=n>>1;
        m=(m*m)%k;
    }
    return ans;
}

int main()
{

    int a;
    int b;
    while(cin>>a>>b)
    {
        cout<<quickpow(a,b,10)<<endl;

    }
    return 0;
}