用冒泡排序模拟实现qsort函数

阅读量：759 次

发布时间：2019-03-23

本文共 2310 字，大约阅读时间需要 7 分钟。

昨天大概讲解了一下qsort函数及其简单应用。我们再看一遍qsort函数：

void qsort(void * base, int size, int num, int(*cmp)(void *, void *))；

下面我们用冒泡排序模拟实现一下，如下：

#define _CRT_SECURE_NO_WARNINGS 1#include 
   
    #include 
    
     #include 
     
      //void qsort(void * base, int  size, int num, int(*cmp)(void *, void *))struct stu{	char name[20];	int age;};void Swap(char *buf1, char*buf2, int width){	int i = 0;	for (i = 0; i < width; i++)	{		char tmp = *buf1;		*buf1 = *buf2;		*buf2 = tmp;		buf1++;		buf2++;	}}void Bubble_sort(void * base, int size, int width, int(*cmp)(void *, void *)){	int i = 0, j = 0;	for (i = 0; i < size - 1; i++)	{		for (j = 0; j < size - i - 1; j++)		{			//强制类型转换为char *类型，用上宽度width,就可以巧妙地转到不同类型的数据			if (cmp_int((char*)base + j*width, (char*)base + (j + 1)*width)>0)			{				Swap((char*)base + j*width, (char*)base + (j + 1)*width, width);			}		}	}}int cmp_int(const void * e1, const void * e2){	return  *((int *)e1) - *((int *)e2);}int cmp_float(const void * e1, const void * e2){	return (int)(*((float *)e1) - *((float *)e2));}int cmp_stu_by_name(const void * e1, const void * e2){	return strcmp(((struct stu *)e1)->name, ((struct stu *)e2)->name);}int cmp_stu_by_age(const void * e1, const void * e2){	return ((struct stu *)e1)->age - ((struct stu *)e1)->age;}void Print1(struct stu s[3]){	int i = 0;	for (i = 0; i < 3; i++)		printf("%d ", s[i].age);	printf("\n");}void test1(){	int arr[] = { 4, 5, 6, 7, 8, 9, 1, 2, 3, 0 };	int sz1 = sizeof(arr) / sizeof(arr[0]);	Bubble_sort(arr, sz1, sizeof(arr[0]), cmp_int);	int i = 0;	for (i = 0; i < 10; i++)		printf("%d ", arr[i]);	printf("\n");}void test2(){	float brr[] = { 3.0, 2.0, 4.0, 5.0, 7.0, 4.0 };	int sz2 = sizeof(brr) / sizeof(brr[0]);	Bubble_sort(brr, sz2, sizeof(brr[0]), cmp_float);	int i = 0;	for (i = 0; i < 6; i++)		printf("%f ", brr[i]);	printf("\n");}void test3(){	struct stu s[3] = { { "zhangsan", 15 }, { "lisi", 23 }, { "wangwu", 8 } };	int sz3 = sizeof(s) / sizeof(s[0]);	Bubble_sort(s, sz3, sizeof(s[0]), cmp_stu_by_name);	Print1(s);}void test4(){	struct stu s[3] = { { "zhangsan", 15 }, { "lisi", 23 }, { "wangwu", 8 } };	int sz3 = sizeof(s) / sizeof(s[0]);	Bubble_sort(s, sz3, sizeof(s[0]), cmp_stu_by_age);	Print1(s);}int main(){	test1();	test2();	test3();	test4();	return 0;}

今天就简单说到这了。