代码如下：
#include<stdio.h>

double power_positive(double n,int p);
double power_negative(double n,int p);

int main(void)
{
 double x,xpow;
 int exp;
 printf("Enter a number and the integer power to which\n");
 printf("the number will be raised.Enter q to quit.\n");
 while(scanf("%lf %d",&x,&exp)==2)
 {
  if(x==0)
   printf("%lf to the power of %d is 0.\n",x,exp);
  else if(exp==0)
   printf("%lf to the power of %d is 1.\n",x,exp);
  else if(exp>0)
  {
   xpow=power_positive(x,exp);
   printf("%lf to the power of %d is %lf.\n",x,exp,xpow);
  }
  else
  {
   xpow=power_negative(x,exp);
   printf("%lf to the power of %d is %lf.\n",x,exp,xpow);
  }
  printf("Enter next pair of numbers or q to quit.\n");
 }
 printf("Hope you enjoyed this power trip --BYE!\n");

 return 0;

}

double power_positive(double n,int p)
{
 double pow=1;
 if(p>0)
  pow=n*power_positive(n,(p-1));

 return pow;
}

double power_negative(double n,int p)
{
 double pow = 1;
 int q;
 q=-p;

 if(q>0)
  pow = power_negative(n,1-q) / n;

 return pow;
}

}