题解 | 从单向链表中删除指定值的节点

#include <stdio.h>
#include<stdlib.h>
typedef struct Node{
    int value;
    struct Node *next;
}node;
//节点插入函数
void insert(node *head,int later,int prior){
    while(head!=NULL){
        if(prior==head->value){
            node *tmp=(node*)malloc(sizeof(node));
            tmp->value=later;
            tmp->next=head->next;
            head->next=tmp;
            return;
        }
        head=head->next;
    }
    return;
}
//节点遍历函数
void display(node *head){
    while(head!=NULL){
        printf("%d ",head->value);
        head=head->next;
    }
    return;
}

//节点删除函数
void delete(node *head,int num){
    if(head->value==num){
        node *tmp=(node*)malloc(sizeof(node));
        tmp=head;
        head=head->next;
        free(tmp);
    }
    //前驱节点
    /*
    node *current=head;
    node *previous=NULL;
    while(current!=NULL&&(current->value!=num)){
        previous=current;
        current=current->next;
    }
    if(current!=NULL){
        previous->next=current->next;
        free(current);
    }
    */
    
    //后驱节点
    node *head_t=head;
    node *head_t1=head->next;
    while(head_t1!=NULL){
        if(head_t1->value==num){
            head_t->next=head_t1->next;
            free(head_t1);
            break;
        }
        head_t=head_t->next;
        head_t1=head_t->next;
    }
}

//释放动态分配的内存
void free_node(node *head){
    while(head!=NULL){
        node *next=head->next;
        free(head);
        head=next;
    }
    return;
}

int main() {
    int n,head_value,del;
    scanf("%d %d",&n,&head_value);
    //链表初始化
    node *head=(node*)malloc(sizeof(node));
    head->value=head_value;
    head->next=NULL;
    int later,prior;
    while(n>1){
        scanf("%d %d",&later,&prior);
        insert(head,later,prior);
        n--;
    }
    scanf("%d",&del);
    delete(head,del);
    display(head);
    free_node(head);
    return 0;
}