C语言数据结构——链表

C语言数据结构——链表

#include <stdio.h>
#include <stdlib.h>
#define MAXSIZE 100

typedef int ElemType; 

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

Node* initList()
{
	Node *head = (Node*)malloc(sizeof(Node));
	head->data = 0;
	head->next = NULL;
	return head;
}
//初始化

Node* getTail(Node *L)
{
	Node *p =L;
	while(p->next != NULL)
	{
		p = p->next;
	}
	return p;
}
//获得尾部链表

int insertHead(Node *L,ElemType e)
{
	Node *p = (Node*)malloc(sizeof(Node));
	p->data = e;
	p->next = L->next;
	L->next = p;
} 
//头插法

int insertNode(Node *L,int pos,ElemType e)
{
	Node *p = L;
	int i = 0;
	while(i < pos-1)
	{
		p = p->next;
		i++;
		if (p == NULL)
		{
			return 0;
		}
	}
	Node *q = (Node*)malloc(sizeof(Node));
	q->data = e;
	q->next = p->next;
	p->next = q; 
	return 1;
} 
//指定位置插入数据

Node* insertTail(Node *tail,ElemType e)
{
	Node *p = (Node*)malloc(sizeof(Node));
	p->data = e;
	tail->next = p;
	p->next = NULL;
	return p;
}
//尾插法

int deleteNode(Node *L,int pos)
{
	Node *p = L;
	int i = 0;
	while(i < pos-1)
	{
		p = p->next;
		i++;
		if (p == NULL)
		{
			return 0;
		}
	}
	Node *q = p->next;
	p->next = q->next;
	free(q);
	return 1;
} 
//指定位置删除链表

void listNode(Node *L)
{
	Node *p = L->next;
	while(p!=NULL)
	{
		printf("%d ",p->data);
		p = p->next;
	}
	printf("\n");
}
//遍历

int listLength(Node *L)
{
	Node *p = L->next;
	int i = 1;
	while(p->next != NULL)
	{
		p = p->next;
		i++;
	}
	printf("%d\n",i);
	return i;
}
//获取链表长度

void freeNode(Node *L)
{
	Node *p = L->next;
	while(p != NULL)
	{
		Node *q = p->next;
		free(p);
		p = q;
	}
	L->next = NULL;
}
//释放链表（不包括头链表）

int main()
{
	Node *list = initList();
	Node *tail = getTail(list);
	tail = insertTail(tail,10);
	tail = insertTail(tail,20);
	tail = insertTail(tail,30);
	listNode(list);
	insertNode(list,2,15);
	listNode(list);
	deleteNode(list,3);
	listNode(list);
	listLength(list);
	freeNode(list);
	listNode(list);
	return 0;
}