题解 | #【模板】链表#

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct a{
    int data;
    struct a *next;
}arr;
//插入
void input(arr **head,int x,int y){
    arr *phead=*head,*pphead=*head,*zzz;
    if(*head==NULL){
        phead=(arr*)calloc(1,sizeof(arr));
        phead->data=y;
        phead->next=NULL;
        *head=phead;
    }else {
        while(pphead){
            if(pphead->data==x){
                break;
            }else{
                phead=pphead;
                pphead=pphead->next; 
            } 
        }
        if(pphead==*head){
            zzz=(arr*)calloc(1,sizeof(arr));
            zzz->data=y;
            zzz->next=pphead;
            *head=zzz;
        }else{
            zzz=(arr*)calloc(1,sizeof(arr));
            zzz->data=y;
            zzz->next=pphead;
            phead->next=zzz;
        }
    }
}
//删除
void delete(arr **head,int x){
    arr* phead=*head,*pphead=*head,*zzz;
    while(pphead){
        if(pphead->data==x){
            //删
            if(pphead==*head){
                *head=pphead->next;
                free(pphead);
                break;
            }else{
                zzz=pphead->next;
                phead->next=zzz;
                free(pphead);
                break;
            }
            
        }else{
            phead=pphead;
            pphead=pphead->next;
        }
    }
}

int main() {
    int n,x,y;
    char handle[7];
    arr *head=NULL;
    scanf("%d",&n);
    for(int i=0;i<n;i++){
        scanf("%s",handle);
        if(strcmp(handle,"insert")==0){
            scanf("%d%d",&x,&y);
            input(&head,x,y);
        }else if(strcmp(handle,"delete")==0){
            scanf("%d",&x);
            delete(&head,x);
        }
    }
    if(head==NULL){
        printf("NULL");
    }else {
        while(head){
        printf("%d ",head->data);
        head=head->next;
        } 
    }
    return 0;
}