链表操作合集

/**********************链表笔记**********************/
#include <stdio.h>
#include <stdlib.h>

typedef struct node 
{
    int data;
    struct node *next;
    struct node *prior;//双向链表的前驱结点
}LINK;

int main(void)
{
    /**************定义********************/

    int x;//用户输入
    int j;//统计结点数
    int num;//节点序号(结点序号从0开始，head是第0号结点）
    LINK *p, *q, *r, *rB;//指向某结点

    LINK *head = (LINK *)malloc(sizeof(LINK));
    LINK *headB = (LINK *)malloc(sizeof(LINK));
    LINK *headC = (LINK *)malloc(sizeof(LINK));//循环单链表
    head->next = NULL;
    head->prior = NULL;

    /**************头插法*******************/

    /*scanf("%d",&x);
    while(x != -1)
    {
        p = (LINK *)malloc(sizeof(LINK));
        p->data = x;
        p->next = head->next;
        head->next = p;
        scanf("%d",&x);
    }*/

    /*************尾插法*********************/
    
    r = head;
    printf("请输入元素：");
    scanf("%d", &x);
    while(x != -1)
    {
        p = (LINK *)malloc(sizeof(LINK));
        p->data = x;
        r->next = p;//r是上一个结点，p是新的结点
        r = p;//让新结点变成尾结点
        scanf("%d", &x);
    }
    r->next = NULL;
    
    /*************打印链表************/

    p = head;
    printf("head");
    while(p->next != NULL)
    {
        p = p->next;
        printf("->%d", p->data);
    }

    /**************求表长*************/
    /*
    p = head;
    j = 0;
    while(p->next != NULL)
    {
        p = p->next;
        j++;
    }
    printf("\n表长为：%d\n", j);
    */
    /***********按序号查找*************/
    /*
    j = 0;
    printf("请输入查找的结点序号：");
    scanf("%d",&num);
    p = head;
    while(p->next != NULL && j < num)
    {
        p = p->next;
        j++;
    }
    if (j == num)
    {
        printf("第%d个结点为%d\n", num, *p);
    }
    else
    {
        printf("该结点不存在\n");
    }
    */
    /****************按值查找****************/
    /*
    printf("请输入查找的值：");
    scanf("%d", &x);
    while(p->next != NULL && p->data != x)
    {
        p = p->next;
    }
    if(p->data == x)
    {
        printf("%d\n", p->data);
    }
    else
    {
        printf("表中不存在值为%d的结点\n", x);
    }
    */
    /*****************插入*******************/
    /*
    p = head;
    j = 0;
    printf("\n请输入插入结点的位置和值（逗号分隔）：");
    scanf("%d,%d", &num, &x);

    while(p->next != NULL && j != (num - 1))
    {
        p = p->next;
        j++;
    }
    if (p->next == NULL)
    {
        printf("不存在该结点位置\n");
    }
    else
    {
        q = (LINK *)malloc(sizeof(LINK));
        q->data = x;
        q->next = p->next;
        p->next = q;
    }

    p = head;
    printf("head");
    while(p->next != NULL)
    {
        p = p->next;
        printf("->%d", p->data);
    }
    */
    /***************删除*****************/
    /*
    p = head;
    j = 0;
    printf("\n请输入删除的结点序号：");
    scanf("%d", &num);

    while(p->next != NULL && (j < (num - 2)))
    {
        p = p->next;
        j++;
    }
    if (p->next == NULL)
    {
        printf("第%d个结点不存在\n", num - 1);
    }
    else
    {
        p = p->next;//定位到删除结点的前一个结点
    }

    if(p->next == NULL)
    {
        printf("第%d个结点不存在\n", num);
    }

    q = p->next;//q是待删除结点
    if(q->next == NULL)//若q是尾结点
    {
        p->next = NULL;
        free(q);
    }
    else
    {
        p->next = q->next;
        free(q);
    }

    p = head;//打印删除后链表
    printf("head");
    while(p->next != NULL)
    {
        p = p->next;
        printf("->%d", p->data);
    }
    */
    /****************逆置****************/
    /*
    p = head->next;
    head->next = NULL;//原链表置空

    while (p)
    {
        q = p;
        p = p->next;
        q->next = head->next;
        head->next = q;
    }

    p = head;
    printf("\nhead");
    while(p->next != NULL)
    {
        p = p->next;
        printf("->%d", p->data);
    }
    */
    /***************删除重复结点****************/
    /*
    p = head->next;
    if (p == NULL)
    {
        printf("\n空链表");
    }
    else
    {
        while (p->next)
        {
            q = p;
            while (q->next)
            {
                if (q->next->data == p->data)
                {
                    r = q->next;
                    q->next = r->next;
                    free(r);
                }
                else
                {
                    q = q->next;
                }
            }
            p = p->next;
        }
    }

    p = head;
    printf("\nhead");
    while (p->next != NULL)
    {
        p = p->next;
        printf("->%d", p->data);
    }
    */
    /****************两个集合的差集****************/
    /*
    r = headB;//尾插法输入链表B元素
    printf("\n请输入集合B的元素：");
    scanf("%d", &x);
    while (x != -1)
    {
        p = (LINK *)malloc(sizeof(LINK));
        p->data = x;
        p->next = r->next;
        r->next = p;
        r = p;
        scanf("%d", &x);
    }
    r->next = NULL;

    p = headB;//打印链表B
    printf("headB");
    while (p->next)
    {
        p = p->next;
        printf("->%d", p->data);
    }

    q = headB;//差集
    while (q->next)
    {
        q = q->next;
        p = head;
        while (p->next)
        {
            if (p->next->data == q->data)
            {
                r = p->next;
                p->next = r->next;
                free(r);
            }
            else
            {
                p = p->next;
            }
        }
    }

    p = head;//打印差集后链表
    printf("\nhead");
    while (p->next)
    {
        p = p->next;
        printf("->%d", p->data);
    }
    */
    /********************循环单链表******************/
    /*
    r = headC;
    printf("\n请输入循环单链表元素：");
    scanf("%d", &x);

    while (x != -1)
    {
        p = (LINK *)malloc(sizeof(LINK));
        p->data = x;
        p->next = r->next;
        r->next = p;
        r = p;
        scanf("%d", &x);
    }
    r->next = headC;

    p = headC->next;//打印循环单链表
    printf("\nheadC");
    while (p != headC)
    {
        printf("->%d",p->data);
        p = p->next;
    }
    */
    /****************连接两个循环单链表****************/
    /*
    r = head;//循环单链表
    printf("\n请输入循环单链表元素：");
    scanf("%d", &x);
    while(x != -1)
    {
        p = (LINK *)malloc(sizeof(LINK));
        p->data = x;
        p->next = r->next;
        r->next = p;
        r = p;
        scanf("%d",&x);
    }
    r->next = head;

    rB = headB;//循环单链表B
    printf("\n请输入循环单链表B元素：");
    scanf("%d", &x);
    while(x != -1)
    {
        p = (LINK *)malloc(sizeof(LINK));
        p->data = x;
        p->next = rB->next;
        rB->next = p;
        rB = p;
        scanf("%d",&x);
    }
    rB->next = headB;
    
    r->next = headB->next;//连接
    rB->next = head;

    p = head;//打印
    printf("head");
    while(p->next != head)
    {
        p = p->next;
        printf("->%d", p->data);
    }
    */
    /***************双向循环链表*******************/
    /*
    r = head;
    printf("\n请输入双向循环链表的元素：");
    scanf("%d", &x);
    while(x != -1)
    {
        p = (LINK *)malloc(sizeof(LINK));
        p->data = x;
        p->next = r->next;
        p->prior = r;
        r->next = p;
        r = p;
        scanf("%d", &x);
    }
    r->next = head;

    p = head->next;//打印
    printf("head");
    while (p != head)
    {
        printf("->%d", p->data);
        p = p->next;
    }

    p = r;//倒序打印
    printf("\nrear");
    while (p != head)
    {
        printf("->%d", p->data);
        p = p->prior;
    }
    */
    /**************************************/
    return 0;
}