[学习记录]带头指针的单向链表的基本功能

效果

代码

#include "stdio.h"
#include "stdlib.h"

typedef struct linknode {
	int data;
	struct linknode* next;
}LinkNode;

LinkNode* CreateHeadNode(void);//创建头结点
void CreateNewNode(LinkNode* H);//创捷节点
void PrintList(LinkNode* H);//打印链表
void DeleteNode(LinkNode* H, int data);//删除节点
void ReverseList(LinkNode* H);//反转链表
void function(LinkNode* H, int func);//功能汇总函数

int main()
{
	LinkNode* H = CreateHeadNode();
	int func;
	while (1)
	{
		printf("Select function: ");
		scanf_s("%d", &func);
		function(H, func);
		printf("\n");
	}
	return 0;
}

LinkNode* CreateHeadNode(void)
{
	LinkNode* Head = (LinkNode*)malloc(sizeof(LinkNode));
	//Head->num = 0;
	Head->data = 0;
	Head->next = NULL;
	return Head;
}

void CreateNewNode(LinkNode* H)
{
	int data;
	LinkNode* ptr = (LinkNode*)malloc(sizeof(LinkNode));
	ptr->next = H->next;
	H->next = ptr;
	scanf_s("%d", &data);
	ptr->data = data;
	H->data++;
}

void PrintList(LinkNode* H)
{
	LinkNode* ptr = H->next;
	printf("List:	");
	while (ptr != NULL)
	{
		printf("%d\t", ptr->data);
		ptr = ptr->next;
	}
	printf("\n");
}

void DeleteNode(LinkNode* H, int data)
{
	LinkNode* ptr = H->next;
	LinkNode* ptr_last = H;
	while (ptr != NULL && ptr->data != data)//先判空，否则会造成溢出
	{
		ptr_last = ptr;
		ptr = ptr->next;
	}
	if (ptr != NULL && ptr->data == data)//上述两个条件有一个不符合就会进入if判断，所以此处仍要对两个条件判断
	{
		ptr_last->next = ptr->next;
		free(ptr);
		printf("delete successed\n");
	}
	else
		printf("delete failed\n");
}

void ReverseList(LinkNode* H)
{
	LinkNode* ptr = H->next;
	LinkNode* ptr_last = NULL;
	H->next = NULL;
	while (ptr != NULL)
	{
		ptr_last = ptr;
		ptr = ptr->next;
		ptr_last->next = H->next;
		H->next = ptr_last;
	}
}

void function(LinkNode* H, int func)
{
	switch (func)
	{
	case 1:
		printf("ADD\n");
		printf("data: ");
		CreateNewNode(H);
		break;
	case 2:
		printf("DEL\n");
		printf("data: ");
		int data;
		scanf_s("%d", &data);
		DeleteNode(H, data);
		break;
	case 3:
		printf("PRT\n");
		PrintList(H);
		break;
	case 4:
		printf("REV\n");
		ReverseList(H);
		break;
	default:
		printf("ERR\n");
		break;
	}

}