1 #define _CRT_SECURE_NO_WARNINGS 1

 2 #include<stdio.h>

 3 double power(double, int);

 4 int main()

 5 {

 6     double x; int n;

 7     puts("INPUT 'x', 'n'\n");

 8     scanf("%lf%d", &x, &n);

 9     printf("x^n = %lf", power(x, n));

10     return 0;

11 }

12 double power(double x, int n)

13 {

14     int i; double rst = 1;

15     if (n == 0)//i不会小于0

16     {

17         return 1;

18     }

19     else

20     for (i = 1; i <= n; i++)//常规思路

21     {

22         rst = rst * x;

23     }

24     return rst;

25 }

1 double power(double x, int n)//用递归

2 {

3     int i; double rst = 1;

4     if (n == 0) return 1;

5     else return x * power(x, n - 1);

6 }