////  main.m//  c++test////  Created by andyyang on 6/3/13.//  Copyright (c) 2013 andyyang. All rights reserved.////#import 
    
     #include "stdio.h"#include "string.h"int power(double base,int exponent){ if(exponent==0) {     return 1; }    if(exponent==1)    {        return base;    }    if(exponent &0x01)    {        return power(base,exponent>>1)*power(base,exponent>>1)*base;    }else    {        return power(base,exponent>>1)*power(base,exponent>>1);    }}int main(int argc, const char * argv[]){    double ret=power(12, 2);    printf("%f",ret);    getchar();        return 0;}
    

充分利用位运算，高效低实现数值的整数次方