【c基础练习】c语言实现链表

#define _CRT_SECURE_NO_WARNINGS#include<stdio.h>#include<string.h>#include<stdlib.h>typedef struct _LINKNODE{int data;struct _LINKNODE* next;}link_node;//创建节点link_node* init_linklist(){//创建头结点指针link_node* head = NULL;//给头结点分配内存head = (link_node*)malloc(sizeof(link_node));if (head == NULL){return NULL;}head->data = -1;head->next = NULL;//保存当前节点link_node* p_current = head;//向链表中插入节点int data = -1;while (1){printf("please input data:\n");scanf("%d", &data);//如果输入-1，则退出循环if (data == -1){break;}//给新节点分配内存link_node* newnode = (link_node*)malloc(sizeof(link_node));if (newnode == NULL){break;}//给节点赋值newnode->data = data;newnode->next = NULL;//新节点入链表，也就是将节点插入到最后一个节点的下一个位置p_current->next = newnode;//更新辅助指针p_currentp_current = newnode;}return head;}//遍历链表void foreach_linklist(link_node* head){if (head == NULL){return;}//赋值指针变量link_node* p_current = head->next;while (p_current != NULL){printf("%d ", p_current->data);p_current = p_current->next;}printf("\n");}//在val插入节点void insert_linklist(link_node* head, int val, int data){if (head == NULL){return;}//两个辅助指针link_node* p_prev = head;link_node* p_current = p_prev->next;while (p_current != NULL){if (p_current->data == val){break;}p_prev = p_current;p_current = p_prev->next;}//如果p_current为NULL，说明不存在值为val的节点if (p_current == NULL){printf("不存在值为%d的节点!\n", val);return;}//创建新的节点link_node* newnode = (link_node*)malloc(sizeof(link_node));newnode->data = data;newnode->next = NULL;//新节点入链表newnode->next = p_current;p_prev->next = newnode;}//删除值为val的节点void remove_linklist(link_node* head, int val){if (head == NULL){return;}//辅助指针link_node* p_prev = head;link_node* p_current = p_prev->next;//查找值为val的节点while (p_current != NULL){if (p_current->data == val){break;}p_prev = p_current;p_current = p_prev->next;}//如果p_current为NULL，表示没有找到if (p_current == NULL){return;}//删除当前节点： 重新建立待删除节点(p_current)的前驱后继节点关系p_prev->next = p_current->next;//释放待删除节点的内存free(p_current);}//销毁链表void destroy_linklist(link_node* head){if (head == NULL){return;}//赋值指针link_node* p_current = head;while (p_current != NULL){//缓存当前节点下一个节点link_node* p_next = p_current->next;free(p_current);p_current = p_next;}}int main01(){link_node* head;int val = 9;int data = 3;int delval = 6;link_node* init_linklist();remove_linklist(head, delval);insert_linklist(head, val, data);destroy_linklist(head);system("pause");return EXIT_SUCCESS;}