快速幂模版（快速幂取模模版）

快速幂模板

#include<bits/stdc++.h>
using namespace std;
unsigned long long quick_mi(unsigned long long a,unsigned long long b,unsigned long long c)
{
    if(b==1) return a;
    unsigned long long l=quick_mi(a,b/2,c);
    if(b%2==1) return ((l%c)*(l%c)*(a%c));
    else return (l%c)*(l%c);
}

int main()
{
    unsigned long long b,p,k;
    cin>>b>>p>>k;
    if(p==0)
    {
        cout<<b<<"^"<<p<<" mod "<<k<<"="<<1%k;
        return 0;
    }
    cout<<b<<"^"<<p<<" mod "<<k<<"="<<quick_mi(b,p,k)%k;
    return 0;
}