两个高效幂运算对比

#include <iostream>
#include "MyTimer.h"

using namespace std;
int pow(int n,int k){
    if(k==0)  return 1;
    if(k==1)     return n;
    if(k&1) return pow(n*n,k/2)*n;
    return pow(n*n,k/2);
}

int power (int n, int k){//经实测,比pow快
    int ret = n , a = ret;
    --k;
    while (k){
        if (k & 1) ret = ret * a;
        a = a * a;
        k>>=1;
    }
    return ret;
}

int main() {
    int n,k;
    MyTimer mt;
    while (cin>>n>>k){
        mt.Start();
        cout<<pow(n,k);
        mt.Stop();
        cout<<" "<<mt.costTime<<" us "<<endl;
        mt.Reset();
        mt.Start();
        cout<<power(n,k);
        mt.Stop();
        cout<<" "<<mt.costTime<<" us "<<endl;
    }
    return 0;
}