使用C++/C qsort 标准库对结构体进行快速排序

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 typedef struct
 4 {
 5     int date;
 6     int value;
 7 }X_S;
 8 
 9 /* a->z */
10 int cmpfunA2Z(const void * a, const void * b)
11 {
12     X_S * p1 = (X_S *)a;
13     X_S * p2 = (X_S *)b;
14 
15     return p1->value > p2->value;
16 }
17 
18 /* z -> a */
19 int cmpfunZ2A(const void * a, const void * b)
20 {
21     X_S * p1 = (X_S *)a;
22     X_S * p2 = (X_S *)b;
23 
24     return p1->value < p2->value;
25 }
26 
27 int quickSortOfCpp()
28 {
29     X_S Xlist[100];
30     int Ilist[100];
31     int i = 0;
32     for(i = 0; i < 100; i++)
33     {
34         Xlist[i].date = i+1;
35         double t = (double)i - 50.3;
36         Xlist[i].value = (int)(t * t + 5.6);
37     }
38 
39     for(i = 0; i < 100; i++)
40     {
41         printf("num : %3d, value : %4d
", Xlist[i].date, Xlist[i].value);
42     }
43 
44     qsort(Xlist, 100, sizeof(X_S), cmpfunA2Z);
45     printf("