exampe73__经典C语言100例

【程序73】
题目：反向输出一个链表。　　　
1.程序分析：首先创建一个链表，然后把指针翻转，利用3个指针不断的移动使指针翻转指向
2.程序源代码：

 

// example73.cpp : Defines the entry point for the console application.

////


#include "stdafx.h"

#include <stdlib.h>
#include <stdio.h>
struct list
{
    int data;
    struct list *next;
};

typedef struct list node;
typedef node *link;

void displayList(link head){
    link ptr;

    ptr = head->next;
    printf("The list is: Head ->");
    while(ptr != NULL) {
        printf(" %d ->", ptr->data);
        ptr=ptr->next;
    }
    printf("NULL\n");
}

link reverse(link head){
    link ptr, qtr, temp;
    ptr = head->next;
    qtr = ptr->next;
    head = NULL;

    while(ptr->next) {
        ptr->next = head;
        head = ptr;
        ptr = qtr;
        qtr = qtr->next;
    }
    ptr->next = head;

    temp = (link)malloc(sizeof(node));
    temp->next = ptr;
    return temp;
}

int _tmain(int argc, _TCHAR* argv[])
{
    link ptr, head, tail;
    int num,i;
    tail=(link)malloc(sizeof(node));
    tail->next = NULL;
    ptr=tail;
    printf("\nplease input the five node data==>\n");
    for( i = 0; i <= 4; i++ ) {
        printf("The %dth node data: ",(5-i));
        scanf("%d", &num);
        ptr->data = num;
        head = (link)malloc(sizeof(node));
        head->next = ptr;
        ptr = head;
    }
    ptr = ptr->next;


    printf("Before reverse\n");
    displayList(head);
    link newHead = reverse(head);
    printf("After reverse\n");
    displayList(newHead);

    getchar();
    getchar();
    return 0;
}

VS2005实现运行结果如下：

please input the five node data==>
The 5th node data: 5
The 4th node data: 4
The 3th node data: 3
The 2th node data: 2
The 1th node data: 1
Before reverse
The list is: Head -> 1 -> 2 -> 3 -> 4 -> 5 ->NULL
After reverse
The list is: Head -> 5 -> 4 -> 3 -> 2 -> 1 ->NULL