1.什么原理，为什么不会爆ll？

2.时间复杂度怎么分析？

3.担心爆ll，能直接用ull存吗？

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll quick_mul(ll a, ll b, ll p)
{
	ll res = 0;
	while(b)
	{
		if(b & 1) res = (res + a) % p;
		a = (a + a) % p;
		b >>= 1;
	}
	return res;
}
ll quick_pow(ll a, ll b, ll p)
{
	ll ans = 1 % p;
	while(b)
	{
		if(b & 1) ans = quick_mul(ans, a, p) % p;
		a = quick_mul(a, a, p) % p;
		b >>= 1;
	}
	return ans;
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	
	ll a, b, p;
	cin >> a >> b >> p;
	cout << quick_pow(a,b,p) << endl;
	return 0;
}