wikioi 1497--求余运算

#include <iostream>
#include <queue>
#include <climits>
#include <algorithm>
#include <memory.h>
#include <stdio.h>
#include <ostream>
#include <vector>
#include <list>
#include <cmath>
#include <string>
#include <stdexcept>
#include <stack>
#include <map>
using namespace std;

long long pow(long long a,long long b,long long k)
{
    if(b == 0)
        return 1;
    if(b == 1)
        return a%k;
    long long t = pow(a,b>>1);
    if((b&1) == 0)
    {
        return t*t%k;
    }
    else
    {
        return t*t*a%k;
    }
}

int main()
{
    long long b,p,k;
    cin>>b>>p>>k;
    long long b1 = b;
    long long p1 = p;
    //long long ans = pow(b,p);
    //ans = ans%k;
    long long ans = 1;
    b = b%k;
    while(p>0)
    {
        if(p%2 == 1)
            ans = ans*b%k;
        p/=2;
        b = b*b%k;
    }
    cout<<b1<<"^"<<p1<<" mod "<<k<<"="<<ans<<endl;
    return 0;
}