从链表中删除字符串 - C

Question

所以我运行遇到的问题是从充满字符串的链表中删除用户输入的字符串。

我在理解 just 链表的确切工作方式方面仍然存在一些问题，因此对于我做错了什么的任何解释将不胜感激！此外，其他所有功能似乎都运行良好，只是 deleteItem 功能出现问题！

编辑 - 我在运行 deleteItem 功能时遇到的问题只是我的终端 window 在挂机后崩溃。

这是我的代码：

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

struct node
{
    char name[50];
    struct node *next;
}*head;

void display();
void insert();
void count();
void deleteItem();
int main(){

int choice = 1;
char name[50];

struct node *first;
head = NULL;

while(1){
        printf("Menu Options\n");
        printf("----------------\n");
        printf("Please enter the number of the operation you'd like to do: \n");
        printf("----------------\n");
        printf("1. Insert\n");
        printf("2. Display\n");
        printf("3. Count\n");
        printf("4. Delete\n");
        printf("5. Exit\n");
        printf("----------------\n");

        scanf("%d",&choice);

        switch(choice)
            {
            case 1:
                insert();
                break;
            case 2:
                display();
                 break;
            case 3:
                count();
                break;
            case 4:
                if(head=NULL)
                    printf("The list is blank");
                else
                    deleteItem();
                break;
            case 5:
               return 0;
            default:
                printf("invalid option");
            }
        }

        system("pause");
        return 0;
}

void insert(){

 char nameToInsert[50];
 struct node *temp;

temp = head;
 if(head == NULL){
         head = (struct node *)malloc(sizeof(struct node));

         printf("What's the name you wish to insert?\n");
         scanf("%s", &nameToInsert);

         strcpy(head->name, nameToInsert);
         head->next = NULL;
         }

 else{
      while(temp->next !=NULL){
                       temp = temp->next;
                       }
         temp->next = malloc(sizeof(struct node));
         temp = temp->next;

         printf("What's the name you wish to insert?\n");
         scanf("%s", &nameToInsert);

         strcpy(temp->name, nameToInsert);

         temp->next = NULL;
         }

}

void display(){

 struct node *temp;
 temp = (struct node *)malloc(sizeof(struct node));
 temp = head;

 if(temp == NULL)
         printf("The list is empty\n");

 else{
      printf("%s\n", temp->name);

      while(temp->next != NULL){
       temp = temp->next;
       printf("%s\n", temp->name);
       }

 }

}

void count(){
    struct node *temp;
    int c =0;
    temp = head;

    while(temp!=NULL){
        temp=temp->next;
        c++;
    }
    printf("\n%d", c);
}

void deleteItem(){
    char nameToDelete[50];
    struct node *temp, *previous;
    temp = head;

    printf("What is the name you wish to delete?\n");
    scanf("%s", nameToDelete);

    while(temp->next != NULL){
           temp = temp->next;
           if(strcmp(nameToDelete, temp->name)==0){
            previous = temp->next;
            free(temp);
            printf("%s was deleted successfully\n", nameToDelete);
           }

        }

}

Answer 1

我看到以下问题：

你处理的不是要删除的项目在列表头部的情况。
你free包含该项的节点后，链表没有恢复到良好状态。
即使在 free 包含该项目的节点之后，您仍继续遍历列表。

这是一个应该可以使用的版本。

void deleteItem(){
   char nameToDelete[50];
   struct node *temp, *previous;
   temp = head;

   printf("What is the name you wish to delete?\n");
   scanf("%s", nameToDelete);

   // First, locate the node that contains the item.
   for ( ; temp->next != NULL; temp = temp->next )
   {
      if(strcmp(nameToDelete, temp->name)==0)
      {
         break;
      }
      prev = temp;
   }

   // Now take care of deleting it.
   if ( temp != NULL )
   {
      if ( temp == head )
      {
         head = temp->next;
      }
      else
      {
         prev->next = temp->next;
      }

      free(temp);
      printf("%s was deleted successfully\n", nameToDelete);
   }    
}

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