快速幂_2017 NOIP普及组 程序填空第1题
2023-07-31 21:08 作者:windowsxpw | 我要投稿
#include<bits/stdc++.h>
#define int unsigned long long
#pragma GCC optimize(2)
using namespace std;
int fastPower(int base, int exponent) {
if (!exponent) {
return 1;
} else if (exponent==1) {
return base;
} else {
long long half = fastPower(base, exponent>>1);
if (!(exponent&1)){
return half * half;
} else {
return half * half * base;
}
}
}
signed main(){
int a,b;
cin>>a>>b;
cout<<fastPower(a,b);
return 0;
}
虽说递归但还是o(logn)
