实验11-2-4 删除单链表偶数节点 (20 分)

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

struct ListNode {
    int data;
    struct ListNode *next;
};

struct ListNode *createlist();
struct ListNode *deleteeven(struct ListNode *head);
void printlist(struct ListNode *head)
{
    struct ListNode *p = head;
    while (p) {
        printf("%d ", p->data);
        p = p->next;
    }
    printf("\n");
}

int main()
{
    struct ListNode *head;

    head = createlist();
    head = deleteeven(head);
    printlist(head);

    system("pause");
    return 0;
}

/* 你的代码将被嵌在这里 */
struct ListNode *createlist() {
    struct ListNode *head = NULL, *tail = NULL, *p;
    int num;
    scanf("%d", &num);
    while (num != -1) {
        p = (struct ListNode*)malloc(sizeof(struct ListNode));
        p->data = num;
        if (head == NULL) head = tail = p;
        else {
            tail->next = p;
            tail = p;
        }
        scanf("%d", &num);
    }
    tail->next = NULL;
    return head;
}

struct ListNode *deleteeven(struct ListNode *head) {
    struct ListNode *tail, *p;
    while (head&&head->data % 2 == 0) {
        p = head;
        head = head->next;
        free(p);
    }
    tail = head;
    p = tail->next;
    while (p != NULL) {
        if (p->data % 2 == 0) {
            tail->next = p->next;
            free(p);
        }
        else tail = p;
        p = tail->next;
    }
    return head;
}