kk

src/main/java/com/dota/common/TreeNode.java

@@ -5,14 +5,14 @@ public class TreeNode {
 	public TreeNode left;
 	public TreeNode right;
 
-	TreeNode() {
+	public TreeNode() {
 	}
 
-	TreeNode(int val) {
+	public TreeNode(int val) {
 		this.val = val;
 	}
 
-	TreeNode(int val, TreeNode left, TreeNode right) {
+	public TreeNode(int val, TreeNode left, TreeNode right) {
 		this.val = val;
 		this.left = left;
 		this.right = right;

src/main/java/com/dota/tree/_2415/Solution.java

@@ -0,0 +1,39 @@
+package com.dota.tree._2415;
+
+import com.dota.common.TreeNode;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+
+/**
+ * 2415. 反转二叉树的奇数层
+ * <p>
+ * [0,1,2,0,0,0,0,1,1,1,1,2,2,2,2]
+ */
+class Solution {
+	public TreeNode reverseOddLevels(TreeNode root) {
+		ArrayList<TreeNode> list = new ArrayList<>();
+		list.add(root);
+		var flag = false;
+		while (!list.isEmpty()) {
+			var size = list.size();
+			if (flag) {
+				for (int i = 0; i < size / 2; i++) {
+					var t = list.get(i).val;
+					list.get(i).val = list.get(size - 1 - i).val;
+					list.get(size - 1 - i).val = t;
+				}
+			}
+
+			for (int i = 0; i < size; i++) {
+				var treeNode = list.remove(0);
+				if (treeNode.left != null) {
+					list.add(treeNode.left);
+					list.add(treeNode.right);
+				}
+			}
+			flag = !flag;
+		}
+		return root;
+	}
+}