P1226 【模板】快速幂||取余运算

https://www.luogu.com.cn/problem/P1226

#include<cstdio>
#include<iostream>
using namespace std;
#define LL long long int 
LL a,b,m;
int f(LL a,LL b,LL m)
{
	LL sum=1;
	a=a%m;
	while(b)
	{
		if(b&1) sum=(sum*a)%m;
		a=(a*a)%m;
		b=b>>1;
		sum=sum%m;
	}
	return sum%m;
}
int main(void)
{
	cin>>a>>b>>m;
	cout<<a<<"^"<<b<<" mod "<<m<<"=";
	cout<<f(a,b,m);
	return 0; 
}