宅宅情侶的成長日記

分享一下C語言內建的qsort 不太好記，但十分的方便XD

下面是排序身高，體重的範例~

#include <stdio.h>
#include <stdlib.h>

struct Student
{
	char name[8];
	float h , w;
};

void InputStudent(Student *);
void PrintStudent(const struct Student *px);
int cmpH(const void* , const void*);
int cmpW(const void* , const void*);

int main()
{
	size_t n = 0;
	printf("n = ");
	scanf("%Iu" , &n);
	getchar();
	Student *A = (Student*)malloc(n * sizeof(Student));
	
	int i = 0;
	for(i = 0 ; i < n ; i++)
		InputStudent(A + i);
		
	printf("Sorted by height\n");
	qsort(A , n , sizeof(Student) , cmpH);
	
	for(int i = 0 ; i < n ; i++)
		PrintStudent(A + i);
	printf("Sorted by weight\n");
	qsort(A , n , sizeof(Student) , cmpW);
	
	for(int i = 0 ; i < n ; i++)
		PrintStudent(A + i);
	getchar();
}


void InputStudent(Student *px)
{
	scanf("%s %f %f" , px->name , &px->h , &px->w);
}

void PrintStudent(const struct Student *px)
{
	printf("Name:%s , h:%f , w:%f\n" , px->name , px->h , px->w);	
}

int cmpH(const void *p1 , const void *p2)
{
	const Student* ps1 = (const Student*) p1;
	const Student* ps2 = (const Student*) p2;
	return (int)(ps1->h - ps2->h);
}

int cmpW(const void *p1 , const void *p2)
{
	const Student* ps1 = (const Student*) p1;
	const Student* ps2 = (const Student*) p2;
	return (int)(ps1->w - ps2->w);
}