代码如下

#include<iostream>
#include<cstdio>
#define L long
#define LL long long
using namespace std;
inline long long Qpow(long a, long n) {
	if (a == 0 ) return 0;
	else if (n == 0) return 1;
	long long ans = 1;
	while (n) {
		if (n & 1) {
			//9^5 == 9^4 * 9
			ans=ans*a;
			n--;
		}
		ans = ans*ans;
		n >>= 1;
	}
	return ans;
}



int q;
int a;
int b;

int main() {
	std::ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	cin >> a >> b >> q;
	cout << a << "^" << b << " mod " << q << "=" << Qpow(a, b)%q;
	return 0;
}

盯着看了2天不会改，问朋友朋友不屑改，骂我fw，qswl