/*----------------------------------------

     qsorter.c -- 用 qsort() 排序一组数字

 ----------------------------------------*/

 #include <stdio.h>

 #include <stdlib.h>        //提供函数 rand() 原型

 #define NUM 40

 void fillarray(double ar[], int n);

 void showarray(const double ar[], int n);

 int mycomp(const void *p1, const void *p2);

 int main()

 {

     double vals[NUM];

     fillarray(vals, NUM);

     puts("Random list:");

     showarray(vals, NUM);

     qsort(vals, NUM, sizeof(double), mycomp);

     puts("\nSorted list:");

     showarray(vals, NUM);

     return ;

 }

 void fillarray(double ar[], int n)

 {

     for (int index = ; index != n; ++index)

         ar[index] = (double)(rand()) / ((double)(rand()) + 0.1);

 }

 void showarray(const double ar[], int n)

 {

     int index = ;

     for (; index != n; ++index)

     {

         printf("%9.4f ", ar[index]);

         if (index %  == ) putchar('\n');

     }

     if (index %  != ) putchar('\n');

 }

 int mycomp(const void *p1, const void *p2)

 {

     const double *a1 = (double*)p1;

     const double *a2 = (double*)p2;

     if (*a1 > *a2)

         return ;

     else if (*a1 == *a2)

         return ;

     else

         return -;

 }