一刷143

Author: diguage

README.adoc

@@ -1027,12 +1027,12 @@ TIP: **公众号的微信号是: `jikerizhi`**。__因为众所周知的原因
 |Medium
 |
 
-//|{counter:codes}
-//|{leetcode_base_url}/reorder-list/[143. Reorder List^]
-//|{source_base_url}/_0143_ReorderList.java[Java]
-//|{doc_base_url}/0143-reorder-list.adoc[题解]
-//|Medium
-//|
+|{counter:codes}
+|{leetcode_base_url}/reorder-list/[143. Reorder List^]
+|{source_base_url}/_0143_ReorderList.java[Java]
+|{doc_base_url}/0143-reorder-list.adoc[题解]
+|Medium
+|
 
 |{counter:codes}
 |{leetcode_base_url}/binary-tree-preorder-traversal/[144. Binary Tree Preorder Traversal^]

docs/0143-reorder-list.adoc

@@ -1,35 +1,75 @@
 [#0143-reorder-list]
-= 143. Reorder List
+= 143. 重排链表
 
-{leetcode}/problems/reorder-list/[LeetCode - Reorder List^]
+https://leetcode.cn/problems/reorder-list/[LeetCode - 143. 重排链表 ^]
 
-Given a singly linked list _L_: _L_~0~→_L_~1~→…→_L_~_n_-1~→_L_~n~,
+给定一个单链表 `L` 的头节点 `head` ，单链表 `L` 表示为：
 
+....
+L0 → L1 → … → Ln - 1 → Ln
+....
 
-reorder it to: _L_~0~→_L_~_n_~→_L_~1~→_L_~_n_-1~→_L_~2~→_L_~_n_-2~→…
+请将其重新排列后变为：
 
-You may *not* modify the values in the list's nodes, only nodes itself may be changed.
+....
+L0 → Ln → L1 → Ln - 1 → L2 → Ln - 2 → …
+....
 
-*Example 1:*
+不能只是单纯的改变节点内部的值，而是需要实际的进行节点交换。
 
-[subs="verbatim,quotes,macros"]
-----
-Given 1->2->3->4, reorder it to 1->4->2->3.
-----
+*示例 1：*
 
-*Example 2:*
+image::images/0143-01.png[{image_attr}]
 
-[subs="verbatim,quotes,macros"]
-----
-Given 1->2->3->4->5, reorder it to 1->5->2->4->3.
+....
+输入：head = [1,2,3,4]
+输出：[1,4,2,3]
+....
 
-----
+*示例 2：*
+
+image::images/0143-02.png[{image_attr}]
+
+....
+输入：head = [1,2,3,4,5]
+输出：[1,5,2,4,3]
+....
+
+*提示：*
 
+* 链表的长度范围为 `[1, 5 * 10^4^]`
+* `+1 <= node.val <= 1000+`
 
 
+== 思路分析
+
+. 寻找中点
+. 链表反转
+. 合并链表
+
 [[src-0143]]
+[tabs]
+====
+一刷::
++
+--
 [{java_src_attr}]
 ----
 include::{sourcedir}/_0143_ReorderList.java[tag=answer]
 ----
+--
+
+// 二刷::
+// +
+// --
+// [{java_src_attr}]
+// ----
+// include::{sourcedir}/_0143_ReorderList_2.java[tag=answer]
+// ----
+// --
+====
+
+
+== 参考资料
+
 

docs/images/0143-01.png

@@ -368,7 +368,7 @@ include::0141-linked-list-cycle.adoc[leveloffset=+1]
 
 include::0142-linked-list-cycle-ii.adoc[leveloffset=+1]
 
-// include::0143-reorder-list.adoc[leveloffset=+1]
+include::0143-reorder-list.adoc[leveloffset=+1]
 
 include::0144-binary-tree-preorder-traversal.adoc[leveloffset=+1]
 

docs/images/0143-02.png

@@ -245,6 +245,11 @@ endif::[]
 |{doc_base_url}/0415-add-strings.adoc[题解]
 |✅ 双指针
 
+|{counter:codes2503}
+|{leetcode_base_url}/reorder-list/[143. Reorder List^]
+|{doc_base_url}/0143-reorder-list.adoc[题解]
+|✅ 双指针+链表反正+链表合并
+
 |===
 ˚
 截止目前，本轮练习一共完成 {codes2503} 道题。

docs/index.adoc

@@ -0,0 +1,51 @@
+package com.diguage.algo.leetcode;
+
+import com.diguage.algo.util.ListNode;
+import com.diguage.util.ListNodes;
+
+import java.util.Arrays;
+
+public class _0143_ReorderList {
+  // tag::answer[]
+  /**
+   * @author D瓜哥 · https://www.diguage.com
+   * @since 2025-04-13 22:09:48
+   */
+  public void reorderList(ListNode head) {
+    ListNode slow = head, fast = head;
+    while (fast != null && fast.next != null) {
+      slow = slow.next;
+      fast = fast.next.next;
+    }
+    ListNode reversed = reverse(slow.next, null);
+    slow.next = null;
+    ListNode next = head.next;
+    boolean order = false;
+    ListNode curr = head;
+    while (next != null && reversed != null) {
+      if (order) {
+        curr.next = next;
+        next = next.next;
+      } else {
+        curr.next = reversed;
+        reversed = reversed.next;
+      }
+      curr = curr.next;
+      order = !order;
+    }
+    curr.next = next;
+  }
+
+  private ListNode reverse(ListNode head, ListNode pre) {
+    if (head == null) {
+      return pre;
+    }
+    ListNode result = reverse(head.next, head);
+    head.next = pre;
+    return result;
+  }
+  // end::answer[]
+  public static void main(String[] args) {
+    new _0143_ReorderList().reorderList(ListNodes.build(Arrays.asList(1, 2, 3, 4, 5)));
+  }
+}