带有虚拟头java的链表

Question

我正在尝试从带有虚拟头的单链表中删除数据元素。该列表可以包含空数据元素，这就是我卡住的部分。传入的数据是Object类型的。这就是我目前所得到的

public boolean remove(Object o) {
  ListNode prev= this.head, cur = this.head.next;
  if(size == 0)
     return false;
  while(!cur.data.equals(o)){
     prev = cur;
     cur = cur.next;
     return false;
    }
  if(cur == null)//not existing
     return false;
  prev.next = cur.next;
  this.size--;
    return true; //change this as you need.
}

这是链表类

public class MyLinkedList {

private ListNode head;
private int size;

//inner class for ListNode
private class ListNode {
    private Object data;
    private ListNode next;
    private ListNode(Object d) {
        this.data = d;
        this.next = null;
    }
}

public MyLinkedList() {
    this.head = new ListNode(null); //with a dummy head node
    this.size = 0;
}

Answer 1

首先，在访问curr的数据之前添加null检查。还要删除while 循环中的return false，因为它会提前结束循环而不检查列表中的所有元素。

public boolean remove(Object o) {
  ListNode prev= this.head, cur = this.head.next;
  if(size == 0 || cur ==null) // add null check here
     return false;
  while(cur.data!=null && !cur.data.equals(o)){
     prev = cur;
     cur = cur.next;
     //return false; 
    }
  if(cur == null)//not existing
     return false;
  prev.next = cur.next;
  this.size--;
    return true; //change this as you need.
}