输出链表的中间结点

本次程序可输出链表的中间结点的数据。

  1 #define _CRT_SECURE_NO_WARNINGS 1
  2 #include <stdio.h>
  3 #include <stdlib.h>
  4 struct Node {
  5     int data;
  6     struct Node* next;
  7 };
  8 
  9 struct Node* CreateList()
 10 {
 11     struct Node* headNode = (struct Node*)malloc(sizeof(struct Node));
 12     headNode->next = NULL;
 13     return headNode;
 14 }
 15 
 16 struct Node* CreateNode(int data)
 17 {
 18     struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));
 19     newNode->data = data;
 20     newNode->next = NULL;
 21     return newNode;
 22 }
 23 
 24 int ListLength(struct Node* headNode)
 25 {
 26     int len = 0;
 27     while (headNode)
 28     {
 29         headNode = headNode->next;
 30         len++;
 31     }
 32     return len;
 33 }
 34 
 35 void InsertNode(struct Node* headNode, int index, int data)
 36 {
 37     if (!headNode || index <= 0 || index > ListLength(headNode)) {
 38         return -1;
 39     }
 40     else if (index == 1) {
 41         struct Node* newNode = CreateNode(data);
 42         newNode->next = headNode->next;
 43         headNode->next = newNode;
 44     }
 45     else {
 46         struct Node* temp = headNode;
 47         for (int i = 0; i < index - 1; i++) {
 48             temp = temp->next;
 49         }
 50         struct Node* newNode = CreateNode(data);
 51         newNode->next = temp->next;
 52         temp->next = newNode;
 53     }
 54 }
 55 
 56 void PrintList(struct Node* headNode)
 57 {
 58     struct Node* pMove = headNode->next;
 59     while (pMove)
 60     {
 61         printf("%d ", pMove->data);
 62         pMove = pMove->next;
 63     }
 64     printf("\n");
 65 }
 66 
 67 void MiddleDataOfList(struct Node* headNode)  //输出中间结点的数据
 68 {
 69     struct Node* posNode = headNode;
 70     int i, len;
 71     if (!headNode) {
 72         return -1;
 73     }
 74     len = ListLength(headNode) / 2;
 75     for (i = 0; i < len; i++) {
 76         posNode = posNode->next;
 77     }
 78     printf("中间结点的数据是：%d\n", posNode->data);
 79 }
 80 
 81 int main()
 82 {
 83     int i, pos, data, k;
 84     struct Node* pl = CreateList();
 85     while (1)
 86     {
 87         printf("1.往链表中输入数据；2.打印链表；3.打印中间结点；4.退出：");
 88         scanf("%d", &i);
 89         if (i == 1) {
 90             printf("请输入你想要添加的位置：");
 91             scanf("%d", &pos);
 92             printf("请输入你想要添加的数据：");
 93             scanf("%d", &data);
 94             InsertNode(pl, pos, data);
 95         }
 96         else if (i == 2) {
 97             printf("链表为：\n");
 98             PrintList(pl);
 99         }
100         else if (i == 3) {
101             MiddleDataOfList(pl);
102         }
103         else if (i == 4) {
104             break;
105         }
106     }
107     return 0;
108 }

 

posted @ 2021-05-24 23:37  EvanTheBoy  阅读(74)  评论(0)  编辑  收藏  举报