（算法设计技巧与分析）Exprec

#include<iostream>
#include<time.h>
using namespace std;
int power(int x,int n);
int main()
{
int x,n;//n非负
srand((unsigned int(time(NULL))));//导入时间种子加每次运行结样试下伪随机数种子
x=rand()%10;
n=rand()%10;
cout<<x<<"^"<<n<<"="<<power(x,n);
return 0;
}
int power(int x,int n)
{
if(n==0)return 1;
else
{
int y=power(x,n/2);
if(n%2)
return y*y*x;
return y*y;
}
}