Java:需要了解LinkNode构造函数和支持函数

Question

我已经开始研究Java中的LinkedList问题。我遇到了LinkNode，这让我感到困惑。我在下面的leetcode：https://leetcode.com/problems/odd-even-linked-list/discuss/78079/Simple-O(N)-time-O(1)-space-Java-solution找到了问题的解决方案。我想了解更多关于LinkNode的信息。另外，执行下面的函数需要什么样的支持函数？

public class Solution {
public ListNode oddEvenList(ListNode head) {
    if (head != null) {
    
        ListNode odd = head, even = head.next, evenHead = even; 
    
        while (even != null && even.next != null) {
            odd.next = odd.next.next; 
            even.next = even.next.next; 
            odd = odd.next;
            even = even.next;
        }
        odd.next = evenHead; 
    }
    return head;
}}

Answer 1

它已经由LeetCode在他们的模板中定义了，你不需要编写代码：

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode() {}
 *     ListNode(int val) { this.val = val; }
 *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
 * }
 */
class Solution {
    public ListNode oddEvenList(ListNode head) {
        
    }
}

你的代码很好，它会通过：

class Solution {
    public ListNode oddEvenList(ListNode head) {
        if (head != null) {
            ListNode odd = head;
            ListNode even = head.next;
            ListNode evenHead = even;

            while (even != null && even.next != null) {
                odd.next = odd.next.next;
                even.next = even.next.next;
                odd = odd.next;
                even = even.next;
            }

            odd.next = evenHead;
        }

        return head;
    }
}

例如，如果您想在本地测试，可以创建一个名为b.java的文件

import java.util.*;
import javafx.util.*;

class Solution {
    public ListNode oddEvenList(ListNode head) {
        if (head != null) {
            ListNode odd = head;
            ListNode even = head.next;
            ListNode evenHead = even;

            while (even != null && even.next != null) {
                odd.next = odd.next.next;
                even.next = even.next.next;
                odd = odd.next;
                even = even.next;
            }

            odd.next = evenHead;
        }

        return head;
    }
}


class b {
    public static void main(String[] args) {
        Solution object = new Solution();
        System.out.println(object);
    }
}


class ListNode {
    int val;
    ListNode next;
    ListNode() {}
    ListNode(int val) { this.val = val; }
    ListNode(int val, ListNode next) { this.val = val; this.next = next; }
}

然后写你的代码，不管你想怎么测试它。