回调函数的应用（qosrt）并自己实现

#include <stdio.h> //qosrt函数的使用者得实现一个比较函数 int int_cmp(const void * p1, const void * p2) { return (*( int *)p1 > *(int *) p2); } int main() { int arr[] = { 1, 3, 5, 7, 9, 2, 4, 6, 8, 0 }; int i = 0; qsort(arr, sizeof(arr) / sizeof(arr[0]), sizeof (int), int_cmp); for (i = 0; i< sizeof(arr) / sizeof(arr[0]); i++) { printf("%d ", arr[i]); } printf("\n"); system("pause"); return 0; }

MY_qsort

#include<stdio.h> int int_comp(void *p,void *q) { return (*(int *)p>*(int *)q); } void swap(void *p,void *q,int size) { int i = 0; for (i = 0; i < size; i++) { char temp = *((char*)p+i); *((char*)p + i) = *((char*)q + i); *((char*)q + i) = temp; } } void my_qsort(int *arr,int len,int size,int (*int_comp)(void *,void *)) { int i = 0; int j = 0; for (i = 0; i < len - 1; i++) { for (j = 0; j < len - i - 1; j++) { if (int_comp((char *)arr + j*size, (char *)arr + (j + 1)*size) > 0) { swap((char *)arr + j*size, (char *)arr + (j + 1)*size, size); } } } } int main() { int arr[] = {1,3,5,7,9,2,4,6,8,0}; int i = 0; int len = sizeof(arr) / sizeof(sizeof(arr[0])); int size = sizeof(int); my_qsort(arr,len,size,int_comp); for (i = 0; i < len; i++) { printf("%d",arr[i]); } printf("\n"); system("pause"); return 0; }