读书笔记--快速排序

#include <stdio.h>
#include <stdlib.h>
typedef int Item;

#define key(A) (A)
#define less(A,B) (key(A) < key(B))
#define exch(A,B) { Item t = A; A = B; B = t;}

int partition(Item a[], int l,int r) //划分
{
int i = l-1,j = r; Item v = a[r];
while(i!=j)
{
while (less(a[++i],v));
while (less(v,a[--j])) if (j == l) break;
if(i >= j)break;
exch(a[i],a[j]);
}
exch(a[i],a[r]);
return i;
}

void QuickSort(Item a[],int l,int r) //递归调用
{
int i;
if(r <= l) return;
i = partition(a,l,r);
QuickSort(a,l,i-1);
QuickSort(a,i+1,r);
}

int main()
{

int a[10]={9,8,7,5,6,4,2,1,3,0};
QuickSort(a,0,9);
for(int i = 0; i < 10; i++) printf("%3d", a[i]);
printf("\n");
return 0;
}