Question

您了解我为什么在这里调用delete函数时输出变成无限循环的原因吗？没有该功能，代码将起作用。

int main(){

    node *head = NULL;

    end(&head);
    begin(&head);
    begin(&head);
    end(&head);
    begin(&head);
    end(&head);
    begin(&head);
    delete(&head);
    display(head);

    return 0;
}

void delete(node **head){
    node *tmp,*prev = NULL;
    int num;
    printf("Insert the number that you want to delete: ");
    scanf("%d",&num);
    tmp = *head;
    if (tmp->data == num){
        *head = tmp->next;
        free(tmp);
        return;
    }
    while(tmp->data!=num && tmp!=NULL){
        prev = tmp;
        tmp = tmp->next;
    }

    if(tmp == NULL){
        return;
    }
    prev->next = tmp->next;
    free(tmp);
}

这些是我的其他功能：

void begin(node **head){
    node *new;
    int num;
    new = malloc(sizeof(node));
    if(new ==  NULL){
        perror("malloc");
        EXIT_FAILURE;
    }
    printf("Insert number at the beginning: ");
    scanf("%d",&num);
    new->data  = num;
    new->next = *head;
    *head = new;
}

 void end(node **head){
    int num;
    node *tmp,*new;
    new = malloc(sizeof(node));
    if(new == NULL){
        perror("malloc");
        EXIT_FAILURE;
    }
    printf("Insert number at the end: ");
    scanf("%d",&num);
    new->data = num;
    tmp = *head;
    if(tmp == NULL){
        tmp = malloc(sizeof(node));
        tmp->data = num;
        tmp->next = NULL;
    }
    while(tmp->next!=NULL){
        tmp = tmp->next;
    }
    new->next = NULL;
    tmp->next = new;
}


void display(node *head){
    node *tmp;
    if(head == NULL){
        printf("Empty list");
    }
    else{
        while(tmp!=NULL){
            printf("%d ",tmp->data);
            tmp = tmp->next;
        }
    }
}

Answer 1

temp！= NULL条件应在while循环内位于temp-> data！= num之前。因为如果temp到达列表的末尾而没有任何匹配，则temp将为NULL，并且您将没有NULL指针的检查值（temp-> data！= num）。

Answer 2

好的，我明白问题所在。我忘记在tmp = head函数的else{}条件下添加display()

链表中的删除功能

2 个答案: