单链表的基本操作（建立.遍历.添加.删除）

有n个元素，我们把他们用链表表示，执行一些操作在某个位置添加一个数，或者删除某个位置的数；

输入合法的代码：

#include<iostream>
#include<stdio.h>
#include<stdlib.h>
using namespace std;
struct node
{
    int date;
    struct node *next;
};

node *CreatList(node *head, int n);
void TravList(node *head);
node *AddList(node *head, int n, int pos, int num);
node *DelList(node *head, int n, int pos);

int main()
{
    int n, pos, num;
    node *head;
    while(scanf("%d", &n)!=EOF)
    {
        head = (node*)malloc(sizeof(node));

        head = CreatList(head, n);
        TravList(head);

        scanf("%d %d",&pos, &num);///在第pos个位置插入num；
        head = AddList(head, n+1, pos, num);
        TravList(head);

        scanf("%d", &pos);///删除第pos个位置的数；
        head = DelList(head, n+1, pos);
        TravList(head);

    }
    return 0;
}
node *CreatList(node *head, int n)
{
    head->next = NULL;
    for(int i=1; i<=n; i++)
    {
        node *p;
        p = (node *)malloc(sizeof(node));
        scanf("%d", &p->date);
        p->next = head->next;
        head->next = p;
    }
    return head;
}
void TravList(node *head)
{
    node *real;
    real = head->next;
    while(real != NULL)
    {
        printf("%d ", real->date);
        real = real->next;
    }
    printf("
");
}
node *AddList(node *head, int n, int pos, int num)
{
    node *pre, *p, *q;
    pre = head;
    p = pre->next;
    int i=1;
    while(i<pos)
    {
        pre = p;
        p = p->next;
        i++;
    }
    q = (node*)malloc(sizeof(node));
    q->date = num;
    q->next = pre->next;
    pre->next = q;
    return head;
}
node *DelList(node *head, int n, int pos)
{
    node *pre, *p;
    pre = head;
    p = pre->next;
    int i=1;
    while(i<pos)
    {
        pre = p;
        p = p->next;
        i++;
    }
    pre->next = p->next;
    free(p);
    return head;
}
/*
5
1 2 3 4 5
3 10
1

5 4 3 2 1
5 4 10 3 2 1
4 10 3 2 1
*/

对所有输入都可以的代码：

#include<stdio.h>
#include<stdlib.h>
#define OK 1
#define ERROR 0
typedef int Status;

typedef struct Lnode
{
    int data;
    struct Lnode *next;
} Lnode,*Linklist;

int m=sizeof(Lnode);

Linklist Creatlist(int n);
Linklist CreatlistRear(int n);
void Trealist(Linklist L);
Status Listdel(Linklist L,int k);
Status ListAdd(Linklist L,int num,int x);

Linklist Creatlist(int n)///从表的前面插入；
{
    Linklist head,p;
    int i;
    head=(Linklist)malloc(m);
    head->next=NULL;
    for(i=1;i<=n;i++)
    {
        p=(Linklist)malloc(m);
        scanf("%d",&p->data);
        p->next=head->next;
        head->next=p;
    }
    return head;
}

Linklist CreatlistRear(int n)///从表的后面插入；
{
    Linklist rear,p,head;
    int i;
    head=(Linklist)malloc(m);
    head->next=NULL;
    rear=head;
    for(i=0;i<n;i++)
    {
        p=(Linklist)malloc(m);
        scanf("%d",&p->data);
        rear->next=p;
        rear=p;
    }
    rear->next=NULL;
    return head;
}

void Trealist(Linklist L)///遍历单链表；
{
    Linklist p;
    p=L->next;
    while(p)
    {
        printf("%d ",p->data);
        p=p->next;
    }
    printf("
");
}
Status Listdel(Linklist L,int k)///删除单链表的元素；
{
    int j=1;
    Linklist p=L,q=L->next;
    while(q&&j<k)
    {
        p=q;
        q=q->next;
        j++;
    }
    if((q==0 && j<=k) || k<1 )
        return ERROR;
    p->next=q->next;
    free(q);
    return OK;
}
Status ListAdd(Linklist L,int num,int x)///添加单链表的元素；
{
    Linklist p,q,s;
    p=L;
    q=p->next;
    int j=1;
    while(q&&j<x)
    {
        p=q;
        q=q->next;
        j++;
    }
    if((q==0&&j<x)||x<1)
        return ERROR;
    s=(Linklist)malloc(m);
    s->data=num;
    s->next=p->next;
    p->next=s;
    return OK;
}

int main()
{
    int n,k,num,x;
    while(scanf("%d",&n)!=EOF)
    {
        Linklist L;
        //L=Creatlist(n);
        L=CreatlistRear(n);//两种建立链表的方法；
        Trealist(L);
        printf("请输入要删除的位置
");
        scanf("%d",&k);
        int m=Listdel(L,k);
        if(m==1)
            printf("删除成功
");
        else
            printf("删除失败
");
        Trealist(L);
        printf("请输入要插入的数和位置
");
        scanf("%d %d",&num,&x);
        m=ListAdd(L,num,x);
        if(m==1)
            printf("插入成功
");
        else
            printf("插入失败
");
        Trealist(L);
    }
    return 0;
}

包括菜单的:

/*
Time: 2018/6/4
*/

#include<stdio.h>
#include<stdlib.h>
#define OK 1
#define ERROR 0
typedef int Status;

typedef struct Lnode
{
    int data;
    struct Lnode *next;
}Lnode, *Linklist;


Linklist CreateList(int n);///从表的前面插入；
Linklist CreatlistRear(int n);///从表的后面插入；
void TreaveList(Linklist head);///遍历单链表；
Status Add_Ele(Linklist head, int pos, int num);///添加单链表的元素；
Status Del_Ele(Linklist head, int pos);///删除单链表的元素；
Status Find_Ele(Linklist head, int pos, int *e);
Status Alter_Ele(Linklist head, int pos, int num);

int main()
{
    Linklist head;
    int n, num, pos, op;
    Status sta;

    printf("---------------请输入初始链表元素个数:---------------
");
    scanf("%d", &n);
    printf("--------------请输入初始链表的%d个元素:--------------
", n);
    
    head = CreateList(n);//接收函数的返回值，指向新链表的头
    printf("---------------------初始链表:-----------------------
");
    TreaveList(head);//打印单链表
    
    printf("----------输入下面序号对此单链表进行相应操作:--------

");
    printf("---------------------1:添加元素----------------------

");
    printf("---------------------2:删除元素----------------------

");
    printf("---------------------3:查找元素----------------------

");
    printf("---------------------4:修改元素----------------------

");
    printf("-----------------------0:退出------------------------

");

    while(1)
    {
        printf("请输入操作序号...");
        scanf("%d", &op);
        if(op == 0)
            break;
        else if(op == 1)
        {
            printf("请输入需要添加的数和位置(链表下标从1开始，输入的两个数用空格隔开)，请输入...
");
            scanf("%d %d", &num, &pos);
            sta = Add_Ele(head, pos, num);
            if(sta == OK)
            {
                printf("插入成功
");
                printf("插入新元素后的链表为:");
                TreaveList(head);//打印单链表
            }
            else
                printf("插入失败,请检查输入是否合法.
");
        }
        else if(op == 2)
        {
            printf("请输入需要删除元素的位置(链表下标从1开始)，请输入...
");
            scanf("%d", &pos);
            sta = Del_Ele(head, pos);
            if(sta == OK)
            {
                printf("删除成功
");
                printf("删除后的链表为:");
                TreaveList(head);//打印单链表
            }
            else
                printf("删除失败,请检查输入是否合法.
");
        }
        else if(op == 3)
        {
            printf("请输入需要查找元素的下标(链表下标从1开始)，请输入...
");
            scanf("%d", &pos);
            int e;
            sta = Find_Ele(head, pos, &e);
            if(sta == OK)
            {
                printf("查找成功
");
                printf("该位置元素为:%d
", e);
            }
            else
                printf("查找失败,请检查输入是否合法.
");
        }
        else if(op == 4)
        {
            printf("请输入需要修改的位置和数(链表下标从1开始，输入的两个数用空格隔开)，请输入...
");
            scanf("%d %d", &pos, &num);
            sta = Alter_Ele(head, pos, num);
            if(sta == OK)
            {
                printf("修改成功
");
                printf("修改后的链表为:");
                TreaveList(head);//打印单链表
            }
            else
                printf("修改失败,请检查输入是否合法.
");
        }
        printf("
");
    }

    return 0;
}

Linklist CreateList(int n)//头插法
{
    int i;
    Linklist head, s;
    head = (Linklist)malloc(sizeof(Lnode));
    head->next = NULL;
    
    for(i=1; i<=n; i++)
    {
        s = (Linklist)malloc(sizeof(Lnode));
        scanf("%d", &s->data);
        s->next = NULL;
        
        s->next = head->next;
        head->next = s;
    }
    return head;
}

Linklist CreatlistRear(int n)///从表的后面插入；
{
    Linklist rear,p,head;
    int i;
    head = (Linklist)malloc(sizeof(Lnode));
    head->next=NULL;
    rear = head;
    for(i=0; i<n; i++)
    {
        p = (Linklist)malloc(sizeof(Lnode));
        scanf("%d", &p->data);
        p->next = NULL;

        rear->next = p;
        rear = p;
    }
    return head;
}

void TreaveList(Linklist head)
{
    int flag = 0;
    Linklist p = head->next;
    while(p)
    {
        flag = 1;
        printf("%d ", p->data);
        p = p->next;
    }
    if(flag == 0)
        printf("链表为空！");
    printf("
");
}

Status Add_Ele(Linklist head, int pos, int num)
{
    int i=0;
    Linklist p = head, s;
    
    while(p && i<pos-1)
    {
        i++;
        p = p->next;
    }
    if( pos < 1 || !p)
        return ERROR;
    
    s = (Linklist)malloc(sizeof(Lnode));
    s->data = num;
    s->next = p->next;
    p->next = s;
    return OK;
}

Status Del_Ele(Linklist head, int pos)
{
    int i=1;
    Linklist p = head->next, pre = head;
    
    while(i<pos && p)
    {
        i++;
        pre = p;
        p = p->next;
    }
    if(pos < 1 || !p)
        return ERROR;
    pre->next = p->next;
    free(p);
    return OK;
}

Status Find_Ele(Linklist head, int pos, int *e)
{
    int i = 1;
    Linklist p = head->next;
    while(i<pos && p)
    {
        i++;
        p = p->next;
    }
    if(!p || pos<1)
        return ERROR;
    *e = p->data;
    return OK;
}

Status Alter_Ele(Linklist head, int pos, int num)
{
    Linklist p = head->next;
    int i = 1;

    while(i<pos && p)
    {
        i++;
        p = p->next;
    }
    if(!p || pos<1)
        return ERROR;

    p->data = num;
    return OK;
}