一、单链表

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

typedef struct Node {
	int data;
	Node *next;
}Node;

Node* initList()
{
	Node *list = (Node*)malloc(sizeof(Node));
	list->data = 0;
	list->next = NULL;
	return list;
}

void headInsert(Node* L, int data)
{
	Node *node = (Node*)malloc(sizeof(Node));
	node->data = data;
	node->next = L->next;
	L->next = node;
	L->data++;
}

void tailInsert(Node* L, int data)
{
	Node *List = L;
	Node *node = (Node*)malloc(sizeof(Node));
	node->data = data;
	while (List->next)
	{
		List = List->next;
	}
	node->next = List->next;
	List->next = node;
	L->data++;
}

int delete_node(Node* L, int data)
{
	Node *pre = L;
	Node *current = L->next;

	while(current)
	{
		if (current->data==data)
		{
			pre->next = current->next;
			free(current);
			L->data--;
			return true;
		}
		else
		{
			pre = current;
			current = current->next;
		}
	}
	return false;
}

void printList(Node* L)
{
	while (L->next)
	{
		L = L->next;
		printf("node = %d\n", L->data);
	}
}

int main()
{
	Node* L = initList();
	headInsert(L, 1);
	headInsert(L, 2);
	headInsert(L, 3);
	headInsert(L, 4);
	headInsert(L, 5);
	tailInsert(L, 6);
	tailInsert(L, 7);
	printList(L);

	if (delete_node(L, 3)) {
		printf("success delete\n");
	}
	else {
		printf("fail delete\n");
	}
	printList(L);

	system("pause");
	return 0;
}

二、单循环链表

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

typedef struct Node {
	int data;
	Node *next;
}Node;

Node* initList() 
{
	Node *L = (Node*)malloc(sizeof(Node));
	L->next = NULL;
	L->data = 0;
	L->next = L;
	return L;
}

void headInsert(Node* L, int data)
{
	Node *node = (Node*)malloc(sizeof(Node));
	node->data = data;
	node->next = L->next;
	L->next = node;
	L->data++;
}

void tailInsert(Node* L, int data)
{
	Node *List = L;
	Node *node = (Node*)malloc(sizeof(Node));
	while (List->next!=L)
	{
		List = List->next;
	}
	node->data = data;
	node->next = L;
	List->next = node;
	L->data++;
}

int delete_node(Node* L, int data)
{
	Node *pre = L;
	Node *current = L->next;
	while (current!=L)
	{
		if (current->data == data)
		{
			pre->next=current->next;
			free(current);
			L->data--;
			return true;
		}
		else
		{
			pre = current;
			current = current->next;
		}	
	}
	return false;
}

void printList(Node* L)
{
	Node *node = L->next;
	while (node !=L)
	{
		printf("%d->", node->data);
		node=node->next;
	}
	printf("NULL\n");
}
int main()
{
	Node* L = initList();
	headInsert(L, 1);
	headInsert(L, 2);
	headInsert(L, 3);
	headInsert(L, 4);
	headInsert(L, 5);
	tailInsert(L, 6);
	tailInsert(L, 7);
	printList(L);
	delete_node(L, 4);
	delete_node(L, 7);
	printList(L);

	system("pause");
	return 0;
}