数据结构day4-day5线性表之单链表

看配套的PPT

链表的创建

链表的按序号查找

链表尾部插入

一个链表中要包含：数据和节点

段错误：指针非法访问，内存越界

链表按位置取值：

链表插入：

链表的删除：

链表的释放：

linklist.h

typedef int data_t;

typedef struct node{
	data_t data;
	struct node * next;


}listnode, * linklist;


linklist list_create();
int list_tail_insert(linklist H, data_t value);//Head
int list_show(linklist H);
int list_insert(linklist H, data_t value, int pos);//链表在新的位置插入一个节点
linklist list_get(linklist H, int pos);//得到特定位置节点的值
int list_delete(linklist H, int pos);//删除某一位置上的节点
linklist list_free(linklist H);//链表的释放

linklist.c

#include <stdio.h>
#include "linklist.h"
#include <stdlib.h>


linklist list_create()
{
	linklist H;

	H = (linklist)malloc(sizeof(listnode));
	if(H == NULL)
	{
		printf("malloc failed\n");
		return H;
	}

	H->data = 0;
	H->next = NULL;

	return H;
}
int list_tail_insert(linklist H, data_t value)//Head
{
	linklist p;
	linklist q;

	if(H == NULL)
	{
		printf("H is empty\n");
		return -1;
	}

	//1 new node p
	if((p = (linklist)malloc(sizeof(listnode))) == NULL)
	{
		printf("malloc failed\n");
		return -1;
	}
	p->data = value;
	p->next = NULL;
	
	//2 locate tail node
	q = H;
	while(q->next != NULL)
	{
		q = q->next;
	}
	
	//3 insert
	
	q->next = p;
	

	return 0;
}
int list_show(linklist H)
{
	linklist p;
	if(H == NULL)
	{
		printf("H is NULL\n");
		return -1;
	}
	p = H;
	while(p->next != NULL)
	{
		printf("%d ", p->next->data);
		p = p->next;
	}
	puts(" ");
	return 0;
}

int list_insert(linklist H, data_t value, int pos)
{
	linklist p;
	linklist q;
	

	if(H == NULL)
	{
		printf("H is NULL\n");
	}

	//1 locate node p (pos-1)
	p = list_get(H, pos-1);
	
	if(p == NULL)
	{
		return -1;
	}

	//2 new node q
	if((q = (linklist)malloc(sizeof(listnode))) == NULL)
	{
		printf("malloc failed\n");
		return -1;
	}
	q->data = value;
	q->next = NULL;



	//3 insert
	q->next = p->next;
	p->next = q;

	return 0;
}
linklist list_get(linklist H, int pos)
{
	linklist p;
	int i;
	if(H == NULL)
	{
		printf("H is NULL\n");
		return NULL;
	}
	if(pos == -1)
	{
		return H;
	}
	if(pos < -1)
	{
		printf("pos is invalid\n");
		return NULL;
	}

	p = H;

	i = -1;
	while(i < pos)
	{
		p = p->next;
		if(p == NULL)
		{
			printf("pos is invalid\n");
			return NULL;
		}
		i++;
	}


	return p;

}
int list_delete(linklist H, int pos)
{
	linklist p;
	linklist q;

	//1
	if(H == NULL)
	{
		printf("H is NULL\n");
		return -1;
	}

	//2 locate prior找到上一个节点
	p = list_get(H, pos-1);
	if(p == NULL)
		return -1;

	if(p->next == NULL)
	{
		printf("delete pos is invalid\n");
		return -1;
	}
	
	//3 update list
	q = p->next;
	p->next = q->next;

	//4 free
	printf("free:%d\n",q->data);
	free(q);
	q = NULL;	
	
	

	return 0;
}
linklist list_free(linklist H)
{
	linklist p;
	if(H == NULL)
	{
		printf("H is NULL\n");
		return NULL;
	}
	p = H;

	printf("free:");
	while(H != NULL)
	{
		p = H;
		printf("%d ",p->data);
		H = H->next;
		
		free(p);
	}
	puts("");
	return NULL;
}

test.c

#include "linklist.h"
#include <stdio.h>


int test_get(void);
int test_insert(void);
int test_delete(void);
int test_free(void);
int main(int argc, char *argv[])
{
	test_free();
	return 0;
}

int test_get(void)
{
	linklist H;
	linklist p;
	int value;
	H = list_create();
	
	if(H == NULL)
		return -1;

	printf("input:\n");
	while(1)
	{
		scanf("%d",&value);
		if(value == -1)
			break;
		list_tail_insert(H, value);
		printf("input:\n");
	}
	list_show(H);

	p = list_get(H, 0);
	if(p != NULL)
	{
	printf("value:%d\n", p->data);
	}

}
int test_insert(void)
{

	linklist H;
	linklist p;
	int value;
	H = list_create();
	
	if(H == NULL)
		return -1;

	printf("input:\n");
	while(1)
	{
		scanf("%d",&value);
		if(value == -1)
			break;
		list_tail_insert(H, value);
		printf("input:\n");
	}
	list_show(H);

	list_insert(H, 100, 4);
	printf("*******************************\n");
	list_show(H);
	if(p != NULL)
	{
	printf("value:%d\n", p->data);
	}
}
int test_delete(void)
{
	linklist H;
	linklist p;
	int value;
	H = list_create();
	
	if(H == NULL)
		return -1;

	printf("input:\n");
	while(1)
	{
		scanf("%d",&value);
		if(value == -1)
			break;
		list_tail_insert(H, value);
		printf("input:\n");
	}
	list_show(H);

	list_delete(H, 2);
	printf("*******************************\n");
	list_show(H);

}
int test_free(void)
{
    linklist H;
	linklist p;
	int value;
	H = list_create();
	
	if(H == NULL)
		return -1;

	printf("input:\n");
	while(1)
	{
		scanf("%d",&value);
		if(value == -1)
			break;
		list_tail_insert(H, value);
		printf("input:\n");
	}
	list_show(H);

	list_delete(H, 2);
	printf("*******************************\n");
	list_show(H);
	printf("free before:H's position:%p\n",H);
	H = list_free(H);
	printf("free after:H's position:%p\n",H);
}