实验11-2-4 删除单链表偶数节点 (20 分)

1. 题目摘自

https://pintia.cn/problem-sets/13/problems/604

2. 题目内容

本题要求实现两个函数，分别将读入的数据存储为单链表、将链表中偶数值的结点删除。链表结点定义如下：

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

函数接口定义：

struct ListNode *createlist();
struct ListNode *deleteeven( struct ListNode *head );
函数createlist从标准输入读入一系列正整数，按照读入顺序建立单链表。当读到−1时表示输入结束，函数应返回指向单链表头结点的指针。

函数deleteeven将单链表head中偶数值的结点删除，返回结果链表的头指针。

输入样例：

1 2 2 3 4 5 6 7 -1

输出样例：

1 3 5 7

3. 源码参考

#include <iostream>
#include <stdlib.h>

using namespace std;

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);

    return 0;
}

struct ListNode *createlist()
{
  struct ListNode *p, *h, *t;
  int n;

  h = t = NULL;
  cin >> n;
  while(n != -1)
  {
    p = (struct ListNode*)malloc(sizeof(struct ListNode));
    
    p->data = n;
    p->next = NULL;
    
    if(h == NULL)
    {
      h = p;
    }
    else
    {
      t->next = p;
    }

    t = p;
    
    cin >> n;
  }
  
  return h;
}

struct ListNode *deleteeven( struct ListNode *head )
{
  struct ListNode *p;
  
  p = head;
  while(p->next)
  {
    if(p->next->data % 2 == 0)
    {
      p->next = p->next->next;
    }
    else
    {
      p = p->next;
    }
  }

  return head;
}