与虚拟头java的链表

Question

I am trying to remove data elements from a singly linked list with a dummy head. The list can include null data elements, and thats the part where i'm stuck. The data is passed in is of Object type. This is what I got so far

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.
}

this is the linked list class

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

First of all, add a null check before accessing data of curr . Also remove the return false in while loop as it ends your loop prematurely without checking all the elements in list.

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.
}