数据结构之快速排序

参考书籍：严蔚敏《数据结构》

参考视频：李春葆《数据结构》

https://www.icourse163.org/learn/WHU-1001539003?tid=1002049010#/learn/content?type=detail&id=1002711947&sm=1

测试代码：

//希尔排序
#include <stdio.h>
#include <stdlib.h>

#define MAXSIZE 20

typedef struct{ //记录类型 
	int key;    //关键字 
	char data;  //数据
}record;

typedef struct{
	record rec[MAXSIZE+1]; //包含MAXSIZE+1个记录,记录0是哨兵,相当于tmp 
	int length;            //顺序表的长度 
}sqList;

int partition(sqList *L,int low,int high);
void qSort(sqList *L,int low,int high);
 
int main()
{
	sqList L; 
	L.length = MAXSIZE; 
	
	//使用随机数据初始化sqList中的数据
	for(int i = 1;i<=L.length;i++)  
	{
		L.rec[i].key = rand()%23;
		L.rec[i].data = 'a' + L.rec[i].key; 
	}
	
	//输出排序前的记录 
	for(int i = 1;i<=L.length;i++)
		printf("record %2d: key = %2d, data = %c\n",i,L.rec[i].key,L.rec[i].data);
	
	//快速排序
	qSort(&L,1,L.length);
	
	//输出排序后的记录 
	printf("\n------>希尔排序后<------\n");
	for(int i = 1;i<=L.length;i++)
		printf("record %2d: key = %2d, data = %c\n",i,L.rec[i].key,L.rec[i].data);
	
	return 1;
} 

//快速排序分区函数
int partition(sqList *L,int low,int high)
{
	record privotkey;
	L->rec[0] = L->rec[low];
	privotkey.key = L->rec[low].key;
	while(low<high)
	{
		while(low<high && L->rec[high].key>=privotkey.key) --high;
		L->rec[low] = L->rec[high];
		while(low<high && L->rec[low].key<=privotkey.key) ++low;
		L->rec[high] = L->rec[low];
	}
	L->rec[low] = L->rec[0];
	return low;
} 
//快速排序 
void qSort(sqList *L,int low,int high)
{
	record privotloc;
	if(low<high)
	{
		privotloc.key = partition(L,low,high);
		qSort(L,low,privotloc.key-1);
		qSort(L,privotloc.key+1,high);
	}
}

测试结果：

record  1: key = 18, data = s
record  2: key = 21, data = v
record  3: key =  9, data = j
record  4: key =  4, data = e
record  5: key = 10, data = k
record  6: key = 15, data = p
record  7: key =  1, data = b
record  8: key = 10, data = k
record  9: key =  6, data = g
record 10: key = 15, data = p
record 11: key =  1, data = b
record 12: key = 16, data = q
record 13: key =  5, data = f
record 14: key = 14, data = o
record 15: key =  2, data = c
record 16: key =  8, data = i
record 17: key =  5, data = f
record 18: key =  5, data = f
record 19: key = 20, data = u
record 20: key =  8, data = i

------>快速排序后<------
record  1: key =  1, data = b
record  2: key =  1, data = b
record  3: key =  2, data = c
record  4: key =  4, data = e
record  5: key =  5, data = f
record  6: key =  5, data = f
record  7: key =  5, data = f
record  8: key =  6, data = g
record  9: key =  8, data = i
record 10: key =  8, data = i
record 11: key =  9, data = j
record 12: key = 10, data = k
record 13: key = 10, data = k
record 14: key = 14, data = o
record 15: key = 15, data = p
record 16: key = 15, data = p
record 17: key = 16, data = q
record 18: key = 18, data = s
record 19: key = 20, data = u
record 20: key = 21, data = v

--------------------------------
Process exited after 0.1219 seconds with return value 1
请按任意键继续. . .