LeetCode之83. Remove Duplicates from Sorted List

Given a sorted linked list, delete all duplicates such that each element appear only once.

Example 1:

Input: 1->1->2
Output: 1->2

Example 2:

Input: 1->1->2->3->3
Output: 1->2->3

自己的代码：

public static ListNode1 deleteDuplicates(ListNode1 head) {
	if(head == null) return null;
	ListNode1 cur = head;
	ListNode1 first = head;
	
	while(cur != null) {
		
		while(first != null && cur.val == first.val)  // 寻找最近的下一个不同的节点
			first = first.next;
		
		cur.next = first;
		if(cur != null) cur = cur.next; // 注意非空判断
		
	}
	
	return head;
}

别人的代码：

public ListNode deleteDuplicates(ListNode head) {
        if(head == null || head.next == null)return head;
        head.next = deleteDuplicates(head.next);
        return head.val == head.next.val ? head.next : head;
}

        核心思想：递归 -- 大问题 = 当前阶段 + 比大问题小一级的子问题