[LeetCode] 237. Delete Node in a Linked List

轉自LeetCode

Write a function to delete a node (except the tail) in a singly linked list, given only access to that node.

Supposed the linked list is 1 -> 2 -> 3 -> 4 and you are given the third node with value 3, the linked list should become 1 -> 2 -> 4 after calling your function.

<Solution>

這題難的點在於，題目就只給你要刪除 node 的指標

所以無法去改變前一個指標所指的位置

想法如下

• 將下一個 node 的值，複寫到自己身上

• 然後將自己的 next 指標，指到下下個 node

圖解如下

code 如下

C++

	/**
	* Definition for singly-linked list.
	* struct ListNode {
	* int val;
	* ListNode *next;
	* ListNode(int x) : val(x), next(NULL) {}
	* };
	*/
	class Solution {
	public:
	void deleteNode(ListNode* node) {
	node->val = node->next->val;
	node->next = node->next->next;
	}
	};

view raw deleteNodeInSingleLinkedList.cpp hosted with ❤ by GitHub

C++ 還可以簡化成以下

	/**
	* Definition for singly-linked list.
	* struct ListNode {
	* int val;
	* ListNode *next;
	* ListNode(int x) : val(x), next(NULL) {}
	* };
	*/
	class Solution {
	public:
	void deleteNode(ListNode* node) {
	*node = *(node->next);
	}
	};

view raw deleteNodeInSingleLinkedList_2.cpp hosted with ❤ by GitHub

Java

	/**
	* Definition for singly-linked list.
	* public class ListNode {
	* int val;
	* ListNode next;
	* ListNode(int x) { val = x; }
	* }
	*/
	class Solution {
	public void deleteNode(ListNode node) {
	node.val = node.next.val;
	node.next = node.next.next;
	}
	}

view raw deleteNodeInSingleLinkedList.java hosted with ❤ by GitHub