快速排序(C实现)

Posted 2020-06-27

  1 //
  2 //  main.c
  3 //  QSort
  4 //
  5 //  Created by 何进明 on 16/3/22.
  6 //  Copyright © 2016年 bbcai. All rights reserved.
  7 //
  8 
  9 #include<stdio.h>
 10 #include<stdlib.h>
 11 typedef struct Node{
 12     int x;
 13     struct Node *next;
 14 }Node,*List;
 15 void CreateList(int num,List *list){
 16     int i = 0;
 17     List headNode = *list;
 18     List p,r;
 19     r = headNode; // r指向链表的结尾
 20     for(i = 0;i<num;i++)
 21     {
 22         p = (Node *)malloc(sizeof(Node));
 23         scanf("%d",&(p->x));
 24 //        printf("you has been input the %d number:%d\n",i + 1,p->x);
 25         r->next = p;
 26         r = p; //r总是指向当前尾结点
 27     }
 28     r->next = NULL;
 29     *list = (*list)->next;
 30 //    headNode = headNode->next;  /*headNode同样是一个指向头节点指针的局部指针，不能操纵头节点的指针，但是可以操纵头节点指针指向的结构体*/
 31 }
 32 
 33 int NumberInList(List list,int n){
 34     int i = 1;
 35     if(n == 1)
 36     {
 37         return list->x;
 38     }
 39     while(i < n && list !=NULL){
 40         list = list->next;
 41         i ++;
 42     }
 43     return list->x;
 44     
 45 }
 46 void Swap(List *list,int a,int b)
 47 {
 48     printf("开始交换数据\n");
 49     List L = *list;
 50     int tmp1 = 0;
 51     int tmp2 = 0;
 52     int i = 1;
 53     tmp2 = NumberInList(L,b);
 54     while( i < a){  //定位a的结点
 55         i++;
 56         L = L->next;
 57     }
 58     tmp1 = L->x;
 59     L->x = tmp2;
 60     while( i < b)
 61     {
 62         i++;
 63         L = L->next;
 64     }
 65     L->x = tmp1;
 66 }
 67 int Partition(List *list,int low, int high)
 68 {
 69     printf("开始分区\n");
 70     List L = *list;
 71     int mark = low; //假设以第一个为标记
 72     // int mark = L->x; /*这个不行*/
 73     int Markx = NumberInList(L,mark);
 74     while(low < high) /*从表的两端交替向中间扫描*/
 75     {
 76         while(low < high && NumberInList(L,high) >= Markx) /*缺等号会一直不停交换数据，下面一样*/
 77             high --;
 78         Swap(list,low,high);
 79         while(low < high && NumberInList(L,low) <= Markx)
 80             low++;
 81         Swap(list,low,high);
 82     }
 83     return low;
 84 }
 85 void QSort(List *list,int low,int high)
 86 {
 87     printf("开始快排\n");
 88     int mark ;
 89     if(low < high)
 90     {
 91         mark = Partition(list,low,high);
 92         QSort(list,low,mark-1);
 93         QSort(list,mark+1,high);
 94     }
 95 }
 96 int main(int argc, const char * argv[])
 97 {
 98     int num;
 99     List list;
100     list =(Node *)malloc(sizeof(Node));
101     num = 0;
102     scanf("%d",&num);
103     printf("you has been input the total number\n");
104     CreateList(num,&list);
105     QSort(&list,1,num);
106     while (list!=NULL) {
107         printf("%d ",list->x);
108         list = list -> next;
109     }
110     printf("\n that‘s all,thx ");
111     return 0;
112 }

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