三刷101

Author: diguage

docs/0101-symmetric-tree.adoc

@@ -63,15 +63,35 @@ image::images/0101-09.png[{image_attr}]
 
 
 [[src-0101]]
+[tabs]
+====
+一刷::
++
+--
 [{java_src_attr}]
 ----
 include::{sourcedir}/_0101_SymmetricTree.java[tag=answer]
 ----
+--
 
+二刷::
++
+--
 [{java_src_attr}]
 ----
 include::{sourcedir}/_0101_SymmetricTree_2.java[tag=answer]
 ----
+--
+
+三刷::
++
+--
+[{java_src_attr}]
+----
+include::{sourcedir}/_0101_SymmetricTree_3.java[tag=answer]
+----
+--
+====
 
 == 参考资料
 

logbook/202406.adoc

@@ -608,12 +608,12 @@
 |{counter:codes}
 |{leetcode_base_url}/implement-queue-using-stacks/[232. Implement Queue using Stacks^]
 |{doc_base_url}/0232-implement-queue-using-stacks.adoc[题解]
-|❎
+|❌
 
 |{counter:codes}
 |{leetcode_base_url}/isomorphic-strings/[205. Isomorphic Strings^]
 |{doc_base_url}/0205-isomorphic-strings.adoc[题解]
-|❎哈希映射
+|❌哈希映射
 
 |{counter:codes}
 |{leetcode_base_url}/middle-of-the-linked-list/[876. Middle of the Linked List^]
@@ -638,7 +638,12 @@
 |{counter:codes}
 |{leetcode_base_url}/combination-sum-ii/[40. Combination Sum II^]
 |{doc_base_url}/0040-combination-sum-ii.adoc[题解]
-|✔️组合，回溯，剪枝
+|⭕️组合，回溯，剪枝
+
+|{counter:codes}
+|{leetcode_base_url}/symmetric-tree/[101. Symmetric Tree^]
+|{doc_base_url}/0101-symmetric-tree.adoc[题解]
+|⭕️分治
 
 |===
 

src/main/java/com/diguage/algo/leetcode/_0101_SymmetricTree_2.java

@@ -4,6 +4,11 @@
 
 public class _0101_SymmetricTree_2 {
   // tag::answer[]
+
+  /**
+   * @author D瓜哥 · https://www.diguage.com
+   * @since 2024-06-24 16:14
+   */
   public boolean isSymmetric(TreeNode root) {
     return root == null || isSymmetric(root.left, root.right);
   }

src/main/java/com/diguage/algo/leetcode/_0101_SymmetricTree_3.java

@@ -0,0 +1,31 @@
+package com.diguage.algo.leetcode;
+
+import com.diguage.algo.util.TreeNode;
+
+public class _0101_SymmetricTree_3 {
+  // tag::answer[]
+  /**
+   * @author D瓜哥 · https://www.diguage.com
+   * @since 2024-09-16 17:51:17
+   */
+  public boolean isSymmetric(TreeNode root) {
+    if (root == null) {
+      return true;
+    }
+    return isSymmetric(root.left, root.right);
+  }
+
+  private boolean isSymmetric(TreeNode left, TreeNode right) {
+    if (left == null && right == null) {
+      return true;
+    }
+    if (left == null
+      || right == null
+      || left.val != right.val) {
+      return false;
+    }
+    return isSymmetric(left.left, right.right)
+      && isSymmetric(left.right, right.left);
+  }
+  // end::answer[]
+}