LinkList(链表)

　　code：

#include <stdio.h>
#include <time.h>
#include <conio.h>
#include <stdlib.h>

#define INITIA 10

typedef int ElemType;

typedef int Status;

typedef struct Node
{
    ElemType data;
    struct Node * next;
}node;

node * head = NULL, *p, *q;

Status GetElem();
Status LinkListInsert();
Status LinkListDelete();

//获取某个地址的元素
Status GetElem(int i, ElemType e)
{
    int j;
    p = head;
    j = 1;
    while(p && j < i - 1)
    {
        p = p -> next;
        ++j;
    }
    if(!p || j > i)
        return 0;
    e = p -> data;
    printf("%d\n",p -> data);
    return 1;
}
//向链表某位置插入节点
Status LinkListInsert(int i)
{
    int j;
    node * s;
    p = head;
    j = 1;
    while(p && j < i - 1)
    {
        p = p ->next;
        ++j;
    }
    if(!p || j > i)
        return 0;
    s = ( node * ) malloc ( sizeof ( node ) );
    s -> data = rand()%100 + 1;
    s ->next = p -> next, p -> next = s ;
    return 1;
}
//删除链表某节点
Status LinkListDelete(int i, ElemType e)
{
    int j;
    node * s;
    p = head;
    j = 1;
    while(p && j < i - 1)
    {
        p = p -> next;
        ++j;
    }
    if(!p || j > i)
        return 0;
    s = p -> next;
    p -> next = p -> next -> next;
    e = s -> data;
    free(s);
    s = NULL;

    return 1;
}

int main()
{
    char str;
    int i;
    ElemType e = 0;
    srand ( time( 0 ) );
    for(i = 0; i < INITIA; i ++)
    {
        p = ( node * ) malloc ( sizeof ( node ) );
        if(head == NULL)
            head = p;
        else
            q ->next = p;
        p -> next = NULL;
        p -> data = rand()%100 + 1;
        q = p;
    }
    p = head;
    while(p)
    {
        printf("%d ",p -> data);
        p = p -> next;
    }
    printf("\n查找 请按 1   插入数据 请按 2   删除数据 请按 3");
    str = getch();
    if(str == '1')
    {
        printf("\n请输入要查找的数的位置:");
        scanf("%d\n",&i);
        GetElem(i, e);
    }
    if(str == '2')
    {
        printf("\n请输入要插入的数的位置:");    //插在原本该位置上数据的前面
        scanf("%d",&i);
        LinkListInsert(i);
        p = head;
        while(p)
        {
            printf("%d ",p -> data);
            p = p -> next;
        }
    }
    if(str == '3')
    {
        printf("\n请输入要删除的数的位置:");
        scanf("%d",&i);
        LinkListDelete(i, e);
        p = head;
        while(p)
        {
            printf("%d ",p -> data);
            p = p -> next;
        }
    }
    while(head)
    {
        p = head;
        head = head -> next;
        free(p);
    }
    p = NULL;

    return 0;
}

# 2017.8.8

　　前面的测试并不完整，它有一个BUG，比如插入第一位和删除第一位时都不对。

　　解决：

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#include<string.h>
#include<conio.h>

#define N 5

typedef char Element;
typedef int Status;

typedef struct Node
{
    Element data [20];
    struct Node*next;
}Node;

Node*head,*tail,*current;

void Swap();
void Sort();
int length();
Status GetData();
Status InsertNode();
Status DeleteNode();

void Swap(Element*p, Element*q)
{
    Element swap[20];
    strcpy(swap, p),strcpy(p, q),strcpy(q, swap);
}

void Sort(Node*p)
{
    Node*q;
    for(p = head->next; p != NULL; p = p->next)
        for(q = p->next; q != NULL; q = q->next)
            if(*(p->data) > *(q->data))
                Swap(p->data, q->data);
}

int length(Node*p)                //链表长度
{
    int i = 1;
    p = head->next;
    while(p)
    {
        p = p ->next;
        i++;
    }
    return i;
}

Status GetData(Node*p, int i)    //获取某节点数据
{
    int j = 0;
    Element Elem [20];

    p = head->next;

    if(i < 1 || i > length(p))
        return 0;

    while(p && j < i - 1)
    {
        p = p->next;
        j++;
    }

    if(!p || j > i)
        return 0;
    printf("%s\n",strcpy(Elem, p->data));
    return 1;
}

Status InsertNode(Node*p, int i, Element Elem [])
{
    Node*New;
    int j = 1;

    p = head->next;

    if(i == 1)
    {
        New = (Node *)malloc(sizeof(Node));
        strcpy(New->data, Elem);
        New->next = head->next;
        head->next = New;
    }

    if(i < 1 || i > length(p))
        return 0;

    if(i > 1)
    {
        while(p && j < i - 1)
        {
            p = p->next;
            j++;
        }

        if(!p || j > i)
            return 0;

        New = (Node *)malloc(sizeof(Node));
        strcpy(New->data, Elem);
        New->next = p->next;
        p->next = New;
    }
    return 1;
}

Status DeleteNode(Node*p, int i)
{
    int j = 1;
    Node*h;

    p = head->next;

    if(i == 1)
    {
        h = head->next;
        head->next = p->next;
        free(h);
    }

    if(i < 1 || i > length(p))
        return 0;

    if(i > 1)
    {
        while(p && j < i - 1)
        {
            p = p->next;
            j++;
        }

        if(!p || j > i)
            return 0;

        h = p->next;
        p->next = p->next ->next;
        free(h);
    }
    return 1;
}

int main()
{
    int i, Pos;
    char key;
    Element Elem[20];
    Node*p;

    head = (Node *)malloc(sizeof(Node));
    tail = head;
    for(i = 0; i < N; i++)
    {
        current = (Node *)malloc(sizeof(Node));
        gets(current->data);
        tail-> next = current;
        tail = current;
    }
    tail->next = NULL;

    puts("显示数据:");
    p = head->next;
    while(p)
    {
        printf("%s ",p->data);
        p = p->next;
    }
    putchar('\n');

    puts("按 1 由大到小排序    按 2 插入数据");
    puts("按 3 删除数据        按 4 查看某位置的数据");
    puts("按 q 退出程序");
    while((key = getch()) != 'q')
    {
        if(key == '1')
        {
            p = head->next;
            Sort(p);

            p = head->next;
            while(p)
            {
                printf("%s ", p->data);
                p = p->next;
            }
            putchar('\n');
        }
        if(key == '2')
        {
            p = head->next;
            puts("\n");
            printf("请输入要插入的位置/数据:");
            scanf("%d %s",&Pos, Elem);

            InsertNode(p, Pos, Elem);

            puts("插入完毕!\n显示数据:");
            p = head->next;
            while(p)
            {
                printf("%s ", p->data);
                p = p->next;
            }
        }
        if(key == '3')
        {
            p = head->next;
            puts("\n");
            printf("请输入要删除的数据的位置:");
            scanf("%d",&Pos);
            DeleteNode(p, Pos);

            puts("删除完毕!\n显示数据:");
            p = head->next;
            while(p)
            {
                printf("%s ",p->data);
                p = p->next;
            }
        }
        if(key == '4')
        {
            p = head->next;
            printf("请输入要查看的数据的位置:");
            scanf("%d", &Pos);

            puts("查看数据:");
            GetData(p, Pos);
        }
    }

    return 0;
}