我无法从链表中删除所有节点

Question

我正在做一个学校项目，这是关于用单链表做的事情。我现在被困了几个小时，我真的不知道该怎么办。基本上，我的任务是从链表中删除节点。

这是我目前存储在节点中的内容：

1. Jozef Maly 7502110011 1178.88
2. Maria Krasna 6251034526 1636.90
3. Milan Vesely 9512157831 1835.20
4. asd fgh 9862111680 2000.00
5. lol pop 9862111680 2000.00

这是我目前的结果：

Deleted 2 nodes.                           //not really
1. Jozef Maly muz 11.02.1975 1178.88
2. Maria Krasna zena 03.01.1962 1636.90
3. Milan Vesely muz 15.12.1995 1835.20
4. lol pop zena 11.12.1998 2000.00

我的结果应该是这样的：

Deleted 2 nodes.
1. Jozef Maly 7502110011 1178.88
2. Maria Krasna 6251034526 1636.90
3. Milan Vesely 9512157831 1835.20

这是我的代码：

void overRC(struct list *z) {
    int arr[10], notvalidarr[1000];
    int notvalid = 0, x = 0, i = 0, j = 0, k = 0, day, month, year, number;
    int len = length(z); //this function returns the number of nodes

    struct data *temp;
    temp = z->first; //z -> first is the head
    while (temp != NULL) {
        i++;  
        number = temp->ID / 10000;
        for (int j = 0; j < 6; j++) {
            arr[j] = number % 10;
            number /= 10;
        }
        day = 10 * arr[1] + arr[0];
        month = 10 * arr[3] + arr[2];
        year = 1900 + 10 * arr[5] + arr[4];

        if (temp->ID % 11 != 0 || month <= 0 || month > 12 && month < 51 || month > 62 || month == 2 && day > 29 || month <= 7 && month % 2 == 1 && day > 31  || || month <= 7 && month % 2 == 0 && day > 30 || month >= 8 && month % 2 == 0 && day > 31 || month >= 8 && month % 2 == 1 && day > 30) {
            notvalidarr[x++] = i; //i store the positions in this array: 4, 5
        }
        day = 0;
        month = 0;
        year = 0;
        temp = temp->next;
    }

    for (j = 0; j < x; j++) {
        deleteNode(&z->first, notvalidarr[j]);
        notvalid++;
    }
    printf("Deleted %d nodes\n", notvalid);  //it says it deleted 2
}

void deleteNode(struct data **head_ref, int position) { 
    if (*head_ref == NULL) 
        return; 

    struct data *temp = *head_ref; 

    if (position == 1) { 
        *head_ref = temp->next;  
        free(temp);              
        return; 
    } 

    for (int i = 1; i < position - 1; i++) 
        temp = temp->next; 

    if (temp == NULL || temp->next == NULL) 
        return; 

    struct data *next = temp->next->next; 

    free(temp->next);
    temp->next = next; 
}

Answer 1

代码无法编译，因为 notvalidarr 的测试有一个语法错误：|| followed be ||。您应该使用月中天数的最大值数组来简化此测试。

如果 position 太大，deleteNode 函数中可能存在问题，因为您在计算 temp = temp->next;[ 之前没有测试 temp 是否为 null =19=]

调用deleteNode的代码还有一个问题：要移除的节点数组应该从最高位置到最低位置扫描，否则移除节点后位置不正确。

这是更正和简化的版本：

void overRC(struct list *z) {
    static int mdays[13] = { 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
    int deleted = 0;
    struct data **linkp = &z->first;
    struct data *temp;

    while ((temp = *linkp) != NULL) {
        int number = temp->ID / 10000;
        int day = number % 100;
        int month = number / 100 % 100;
        int year = 1900 + number / 10000 % 100;

        if (temp->ID % 11 != 0 ||
            month <= 0 || month > 12 ||
            day <= 0 || day > mdays[month] ||
            (month == 2 && day == 29 && (year == 1900 || year % 4 != 0))) {
            *linkp = temp->next;
            free(temp);
            deleted++;
        } else {
            linkp = &temp->next;
        }
    }
    printf("Deleted %d nodes\n", deleted);
}

我无法从链表中删除所有节点

I'm unable to delete all nodes from a linked list

c

nodes

singly-linked-list