初学数据结构——单链表

    看了一天的数据结构。突然觉得自己太迟没有看到这本书。如果不是要学习并查集，估计我这辈子可能不会去看数据结构这本书。因为单从书名来看，我就觉得是非常深奥的知识，但是能把深奥的知识学懂一点点，也是很快乐的事。

    今天自己写了单链表，虽然和书上的大有不同，但是实现的意义是相同的。
    （>_<觉得自己好蠢，写了一下午才写出来。笨死了！！）

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

typedef int elemtype;

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

typedef struct node *linklist;

linklist create_list(linklist head, elemtype n) //创建链表
{
    linklist pre;
    head = (linklist)malloc(sizeof(Node));
    pre  = (linklist)malloc(sizeof(Node));
    head->next = pre;
    scanf("%d",&pre->data);
    for(int i = 1; i < n; i++)
    {
        pre->next = (linklist)malloc(sizeof(Node));
        pre = pre->next;
        scanf("%d",&pre->data);
    }
    pre->next = NULL;
    return head;
}

linklist add_element_tail(linklist head, elemtype data) //从尾部增加元素
{
    linklist pre,temp;
    pre = head->next;
    temp = (linklist)malloc(sizeof(Node));
    temp->data = data;
    while(pre->next != NULL)
    {
        pre = pre->next;
    }
    pre->next = temp;
    temp->next = NULL;
    return head;
}

linklist add_element_head(linklist head, elemtype data)  //从头部增加元素
{
    linklist pre,temp;
    pre = head->next;
    temp = (linklist)malloc(sizeof(Node));
    temp->data = data;
    head->next = temp;
    temp->next = pre;
    return head;
}

linklist insert_take_place(linklist head, elemtype data, int place) //根据位置增加元素
{
    linklist pre,temp;
    pre = head;
    temp = (linklist)malloc(sizeof(Node));
    temp->data = data;
    for(int i = 0; i < place; i++)
    {
        pre = pre->next;
    }
    temp->next = pre->next;
    pre->next = temp;
    return head;
}

linklist insert_take_value(linklist head, elemtype data, elemtype value) //根据数据值增加元素
{
    linklist pre,temp;
    pre = head->next;  //如果要在值前面插入 请更换此行语句为pre = head;
    temp = (linklist)malloc(sizeof(Node));
    temp->data = data;
    while(pre->data != value)  //如果要在值前面插入 请更换此行语句为pre->next->data == value
    {
        pre = pre->next;
    }
    temp->next = pre->next;
    pre->next =temp;
    return head;
}

void delete_list(linklist &head)  //删除链表
{
    linklist pre;
    while(head != NULL)
    {
        pre = head->next;
        free(head);
        head = pre;
    }
    printf("List was deleted\n");
}

void print_list(linklist head) //打印链表
{
    if(head == NULL)
        printf("No List\n");
    else
    {
        head = head->next;
        while(head != NULL)
        {
            printf("%d ",head->data);
            head = head->next;
        }
        printf("\n");
    }
}


int main()
{
    linklist phead = NULL;
    phead = create_list(phead,10);
    phead = add_element_tail(phead,11);
    phead = add_element_head(phead,12);
    phead = insert_take_place(phead,13,5);
    phead = insert_take_value(phead,14,13);
    print_list(phead);
    delete_list(phead);
    print_list(phead);
    return 0;
}