C语言实现单链表查找中间值

男娘i 2023-05-29 09:18 1阅读 0赞

### C语言实现单链表查找中间值 ###

*   *   *   *  主要功能
             *  实现代码

#### 主要功能 ####

1.  创建单链表
2.  查看链表
3.  查看链表长度
4.  查找单链表中间节点的值

#### 实现代码 ####

#include <stdio.h>
    #include <stdlib.h>
    #include <time.h>
    
    #define ERROR 0
    #define OK 1
    
    typedef struct Node
    { 
        int data; // 数据域
        struct Node* next; // 指针域
    }Node;
    typedef Node* LinkList;
    
    LinkList CreateList(int length); // 创建长度为length的单链表
    int ListLength(LinkList L); //获取单链表长度
    void DisplayList(LinkList L); // 输出单链表
    void CentreValue(LinkList L);  // 查找单链表中间节点的值（高级方法）
    
    int main(int argc, char const *argv[]){ 
        char *help = "=====菜单=====\n1.创建单链表\n2.查看链表\n3.链表长度\n4.查找单链表中间节点的值\n0.退出\n请输入操作序号：";
        int operation = 1;
        LinkList L = NULL;
        while (operation)
        { 
            printf("%s", help);
            scanf("%d", &operation);
    
            switch (operation)
            { 
                case 1:{ 
                    int length;
                    printf("\n请输入要创建链表的长度：");
                    scanf("%d", &length);
                    L = CreateList(length);
                    DisplayList(L);
                    break;
                }
                case 2:
                    DisplayList(L);
                    break;
                case 3:
                    ListLength(L);
                    break;
                case 4:
                    CentreValue(L);
                    break;
            default:
                break;
            }
        }
        
        return 0;
    }
    
    LinkList CreateList(int length){ 
        // 尾插法创建单链表
        LinkList p, rear;
        int i;
        srand(time(0));
        LinkList L = (LinkList)malloc(sizeof(LinkList));
        rear = L;
        for (int i = 0; i < length; i++)
        { 
            p = (Node *)malloc(sizeof(Node)); // 创建中间节点
            p->data = rand() % 100 + 1;
            rear->next = p;
            rear = p; // 移动指针指向尾部
        }
        rear->next = NULL;
         
        return L;
    }
    
    void DisplayList(LinkList L){ 
        LinkList p = NULL, rear;
        rear = L->next;
        while (rear)
        { 
            p = rear;
            printf("%d ", p->data);
            rear = p->next;
        }
        printf("\n\n");
    }
    
    int ListLength(LinkList L){ 
        LinkList p = NULL, rear;
        int i = 0;
        rear = L->next;
        while (rear)
        { 
            p = rear;
            i += 1;
            rear = p->next;
        }
        printf("链表长度为：%d\n\n", i);
    }
    
    void CentreValue(LinkList L){ 
        LinkList mid;
        LinkList search;
        mid = L->next;
        search = L->next;
        while (search)
        { 
            if (search->next == NULL)
            { 
                printf("%d", mid->data);
                break;
            }
            search = search->next->next;
            if (search == NULL)
            { 
                printf("%d %d", mid->data, mid->next->data);
                break;
            }
            mid = mid->next;
        }
        printf("\n\n");
    }