C语言 使用qsort函数来进行快速排序

void qsort(void* base, 
           size_t num, 
           size_t width, 
           int(* compare)(const void* e1, const void* e2)
           );

#include<stdio.h>
#include<stdlib.h>
int cmp_int(const void* e1, const void* e2)
{
	return (*(int*)e1) - (*(int*)e2);
}
 
void test1()
{
	int arr[] = { 1,4,2,6,5,3,7,9,0,8 };
	int sz = sizeof(arr) / sizeof(arr[0]);
	qsort(arr, sz, sizeof(arr[0]), cmp_int);
	int i = 0;
	for (i = 0; i < sz; i++)
	{
		printf("%d ", arr[i]);
	}
	printf("\n");
}
 
int main()
{
	test1();
	return 0;
}

#include<stdio.h>
#include<stdlib.h>
struct Stu
{
	char name[20];
	int age;
	float score;
};
 
int cmp_stu_by_socre(const void* e1, const void* e2)  //结构体中的浮点型
{
	if (((struct Stu*)e1)->score > ((struct Stu*)e2)->score)
	{
		return 1;
	}
	else if (((struct Stu*)e1)->score < ((struct Stu*)e2)->score)
	{
		return -1;
	}
	else
	{
		return 0;
	}
}
 
int cmp_stu_by_age(const void* e1, const void* e2)     //结构体中的整形
{
	return ((struct Stu*)e1)->age - ((struct Stu*)e2)->age;
}
 
int cmp_stu_by_name(const void* e1, const void* e2)    //结构体中的字符型
{
	return strcmp(((struct Stu*)e1)->name, ((struct Stu*)e2)->name);
}
 
void print_stu(struct Stu arr[], int sz)  //打印函数
{
	int i = 0;
	for (i = 0; i < sz; i++)
	{
		printf("%s %d %f\n", arr[i].name, arr[i].age, arr[i].score);
	}
	printf("\n");
}
void test4()
{
	struct Stu arr[] = { {"zhangsan",20,87.5f},{"lisi",22,99.0f},{"wangwu", 10, 68.5f} };
	//按照成绩来排序
	int sz = sizeof(arr) / sizeof(arr[0]);
	qsort(arr, sz, sizeof(arr[0]), cmp_stu_by_socre);
	print_stu(arr, sz);
	qsort(arr, sz, sizeof(arr[0]), cmp_stu_by_age);
	print_stu(arr, sz);
	qsort(arr, sz, sizeof(arr[0]), cmp_stu_by_name);
	print_stu(arr, sz);
}
 
int main()
{
	test4();
	return 0;
}

void bubble(int arr[],int sz)  //冒泡排序实现整形的排序
{
	int tmp = 0; int i = 0; int j = 0;
	for (i = 0; i < sz - 1; i++)
	{
		for (j=0;j<sz-1;j++)
		{
			if (arr[j] > arr[j + 1])
			{
				tmp = arr[j];
				arr[j] = arr[j + 1];
				arr[j + 1] = tmp;
			}
		}
	}
}

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 sz, int width, int(*cmp)(const void* e1, const void* e2))
{
	int i = 0;
	for (i = 0; i < sz - 1; i++)
	{
		int j = 0;
		for (j = 0; j < sz - 1 - i; j++)
		{
			//if (arr[j] > arr[j + 1])
			if (cmp((char*)base + j * width, (char*)base + (j + 1) * width) > 0)
			{
				//两个元素的交换
				Swap((char*)base + j * width, (char*)base + (j + 1) * width, width);
			}
		}
	}
}