C语言单链表的实现

//

//  main.c

//  gfhjhgdf

//

//  Created by chenhao on 13-12-23.

//  Copyright (c) 2013年 chenhao. All rights reserved.

//

#include"stdio.h"

#include <stdlib.h>

typedefstruct List_Node{

int info;

struct List_Node *next;

}node;

//链表长度

int Count_Node(node *head)

{

node *p;

int num = 0;

if (head == NULL)

{

return 0;

}

p = head->next;

while(p!=NULL)

{

num++;

p = p->next;

}

return num;

}

//按值查找

void FindByValue(node *head, int v)

{

node *p;

int i = 0, num = 0;

if (head == NULL)

{

return;

}

p = head->next;

while(p != NULL)

{

i++;

if (p->info == v)

{

num++;

printf("%d ",i);

}

p = p->next;

}

printf("找到%d个等于%d的值",num,v);

}

//插入元素

void InsertItem(node *head, int loc, int num)

{

node *p, *pre, *s;

int i = 0;

if (loc > Count_Node(head)||loc < 0)

{

printf("插入位置错误\n");

return;

}

if (head == NULL)

{

return;

}

pre = head;

p = head->next;

while(i != loc)

{

i++;

pre = p;

p = p->next;

}

s = (node*)malloc(sizeof(node));

s->info = num;

s->next = p;

pre->next = s;

}

//删除元素

int deleteItem(node *head, int loc)

{

node *p, *pre;

int i=1, num=0;

if (loc>Count_Node(head)||loc<=0)

{

printf("删除位置错误\n");

return0;

}

if (head == NULL)

{

return0;

}

pre = head;

p = pre->next;

while(i!=loc)

{

i++;

pre = p;

p=p->next;

}

num = p->info;

pre->next = p->next;

p->next = NULL;

free(p);

return num;

}

//清空链表

void FlushLink(node *head)

{

node *p;

if (head == NULL)

{

return;

}

p = head->next;

head->next = NULL;

free(p);

}

//销毁链表

void DestoryLink(node *head)

{

free(head);

}

//按序号查找

int FindByNo(node *head, int loc)

{

node *p;

int i=1;

if (loc>Count_Node(head)||loc<=0)

{

printf("位置错误\n");

return0;

}

if (head == NULL)

{

return0;

}

p = head->next;

while(i!=loc)

{

i++;

p=p->next;

}

return p->info;

}

//尾插法建立带头结点的单链表

node* Creat_Node()

{

node *head,*pre,*p;

int x;

head=(node*)malloc(sizeof(node));;

head->next=NULL;

pre=head;

printf("输入各结点的值,以0结束:");

while(EOF!=(scanf("%d",&x))&&x!=0)

{

p=(node*)malloc(sizeof(node));

p->info=x;

p->next=pre->next;

pre->next=p;

pre=pre->next;

}

return head;

}

//头插法建立带头结点的单链表

node* Build_Node()

{

node *head,*p;

int x;

head=(node*)malloc(sizeof(node));;

head->next=NULL;

printf("输入各结点的值,以0结束:");

while(EOF!=(scanf("%d",&x))&&x!=0)

{

p=(node*)malloc(sizeof(node));

p->info=x;

p->next=head->next;

head->next=p;

}

return head;

}

//在Y前插入X

void Before_y_Insert_x(node* head,int y,int x)

{

node *pre,*p,*s;

if (head ==NULL)

{

return;

}

pre=head;

p=pre->next;

while(p&&p->info!=y)

{

pre=p;

p=p->next;

}

if(p==NULL)

{

printf("error!%d不在该链表中\n",y);

}

else

{

s=(node*)malloc(sizeof(node));

s->info=x;

s->next=p;

pre->next=s;

}

}

//判断链表是否有序

int Is_Sort(node *head)

{

node *p,*pre;

int flag;

if (head ==NULL)

{

return0;

}

pre=head->next;

p=pre->next;

flag=pre->info>p->info?1:0;

while(p)

{

pre=p;

p=p->next;

if(p)

{

if(flag!=pre->info>p->info?1:0)

{

return 0;

}

}

}

return1;

}

//链表反序

void convert_Node(node *head)

{

node *pre,*p=head->next;

if (head ==NULL)

{

return;

}

head->next=NULL;

while(p)

{

pre=p;

p=p->next;

pre->next=NULL;

pre->next=head->next;

head->next=pre;

}

}

//打印单链表

void Print_Node(node *head)

{

node *p;

if (head ==NULL)

{

return;

}

p=head->next;

printf("输出该链表:");

while(p)

{

printf("%-5d--->",p->info);

p=p->next;

}

if(p==NULL)

{

printf("^\n\n\n");

}

}

void menu()

{

printf("   1:尾插法创建带头节点的链表\n");

printf("   2:头插法创建带头节点的链表\n");

printf("   3:链表长度\n");

printf("   4:在Y前插入X \n");

printf("   5:判断链表是否有序\n");

printf("   6:链表反序 \n");

printf("   7:按值查找\n");

printf("   8:插入元素\n");

printf("   9:删除元素\n");

printf("   10:按序号查找\n");

printf("   11:清空链表\n");

printf("   12:销毁链表\n");

printf("   13:打印链表\n");

printf("   14:退出\n");

}

int main()

{

int goon = 1;

node *head=NULL;//*head1=NULL,*head2=NULL;

int x=0, y=0;

//int flag = 0;

int choice;

menu();

while(goon)

{

printf("请选择：\n");

scanf("%d",&choice);

switch (choice)

{

case 0:

menu();

break;

case 1:

printf("尾插法创建带头节点的链表\n");

head=Creat_Node();

break;

case 2:

printf("头插法创建带头节点的链表\n");

head=Creat_Node();

break;

case 3:

printf("链表长度\n");

printf("链表长度为%d\n",Count_Node(head));

break;

case 4:

printf("在Y前插入X\n请输入X和Y:\n");

scanf("%d%d",&x,&y);

Before_y_Insert_x(head,y,x);

break;

case 5:

printf("判断链表是否有序\n");

if(Is_Sort(head)==1)

{

printf("该链表有序!\n");

}

else

{

printf("该链表无序!\n");

}

break;

case 6:

printf("链表反序\n");

convert_Node(head);

break;

case 7:

printf("按值查找\n请输入要查找的值\n");

scanf("%d",&x);

FindByValue(head,x);

break;

case 8:

printf("插入元素\n请输入插入的位置（0到链表长度之间）和元素");

scanf("%d%d",&x,&y);

InsertItem(head,x,y);

break;

case 9:

printf("删除元素\n请输入删除元素的位置（1到链表长度之间）");

scanf("%d",&x);

printf("删除的元素为%d",deleteItem(head,x));

break;

case 10:

printf("按序号查找\n请输入要查找的序号\n");

scanf("%d",&x);

printf("找到的值为%d",FindByNo(head,x));

break;

case 11:

printf("清空链表\n");

FlushLink(head);

break;

case 12:

printf("销毁链表\n");

DestoryLink(head);

break;

case 13:

Print_Node(head);

break;

case 14:

printf("Exit!");

goon = 0;

break;

default:

break;

}

}

}