2024/8/28 LeetCode Hot100 binaryTree Num543有bug 106案例过101

src/main/java/com/cool/hot100/binary_tree/Num101.java

@@ -0,0 +1,35 @@
+package com.cool.hot100.binary_tree;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/08/28/23:23
+ * DayNumber 4
+ * Hard 1
+ * Level 3
+ */
+public class Num101 {
+
+    public boolean isSymmetric(TreeNode root) {
+        if (root == null) return false;
+        if (root.left != null && root.right != null) {
+            if (root.left.val != root.right.val) return false;
+            else {
+                return isSymmetric(root.left, root.right);
+            }
+        } else return root.left == root.right;
+    }
+
+    public boolean isSymmetric(TreeNode left, TreeNode right) {
+        if (left == right) return true;
+        if (left != null && right != null) {
+            boolean res = (left.val == right.val);
+            if (res) res = isSymmetric(left.left, right.right);
+            if (res) res = isSymmetric(left.right, right.left);
+            return res;
+        }
+        return false;
+    }
+
+}

src/main/java/com/cool/hot100/binary_tree/Num104.java

@@ -0,0 +1,38 @@
+package com.cool.hot100.binary_tree;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/08/28/23:12
+ * DayNumber 2
+ * Hard 1
+ * Level 3
+ */
+public class Num104 {
+
+    private int max=0;
+    private int cur=0;
+    public int maxDepth(TreeNode root) {
+        if(root==null) return max;
+
+        dfs(root);
+        return max;
+    }
+    private void dfs(TreeNode root){
+        if(root==null)return;
+        if(root.left!=null) {
+            cur++;
+            max=Math.max(max,cur);
+            dfs(root.left);
+            cur--;
+        }
+        if(root.right!=null){
+            cur++;
+            max=Math.max(max,cur);
+            dfs(root.right);
+            cur--;
+        }
+    }
+
+}

src/main/java/com/cool/hot100/binary_tree/Num226.java

@@ -0,0 +1,28 @@
+package com.cool.hot100.binary_tree;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/08/28/23:20
+ * DayNumber 3
+ * Hard 1
+ * Level 3
+ */
+public class Num226 {
+
+    public TreeNode invertTree(TreeNode root) {
+        dfsInvertTree(root);
+        return root;
+    }
+
+    private void dfsInvertTree(TreeNode root) {
+        if (root == null) return;
+        TreeNode right = root.right;
+        root.right=root.left;
+        root.left=right;
+        dfsInvertTree(root.left);
+        dfsInvertTree(root.right);
+    }
+
+}

src/main/java/com/cool/hot100/binary_tree/Num543.java

@@ -0,0 +1,28 @@
+package com.cool.hot100.binary_tree;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/08/28/23:52
+ * DayNumber 5
+ * Hard 1
+ * Level 3
+ */
+public class Num543 {
+
+    public int diameterOfBinaryTree(TreeNode root) {
+        if (root == null) return 0;
+        int left = getTreeDeep(root.left);
+        int right = getTreeDeep(root.right);
+        return left + right;
+    }
+
+    private int getTreeDeep(TreeNode root) {
+        if (root == null) return 0;
+        int res = getTreeDeep(root.left);
+        res = Math.max(res, getTreeDeep(root.right));
+        return res + 1;
+    }
+
+}

src/main/java/com/cool/hot100/binary_tree/Num94.java

@@ -0,0 +1,31 @@
+package com.cool.hot100.binary_tree;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/08/28/23:02
+ * DayNumber 1
+ * Hard 1
+ * Level 3
+ */
+public class Num94 {
+
+    public List<Integer> inorderTraversal(TreeNode root) {
+        List<Integer> list=new ArrayList<>();
+        mediumTraverse(root,list);
+        return list;
+    }
+    private void mediumTraverse(TreeNode root,List<Integer> list){
+        if(root==null){
+            return;
+        }
+        mediumTraverse(root.left,list);
+        list.add(root.val);
+        mediumTraverse(root.right,list);
+    }
+
+}

src/main/java/com/cool/hot100/binary_tree/TreeNode.java

@@ -0,0 +1,27 @@
+package com.cool.hot100.binary_tree;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/08/28/23:03
+ * @Description: 二叉树节点
+ */
+public class TreeNode {
+    int val;
+    TreeNode left;
+    TreeNode right;
+
+    TreeNode() {
+    }
+
+    TreeNode(int val) {
+        this.val = val;
+    }
+
+    TreeNode(int val, TreeNode left, TreeNode right) {
+        this.val = val;
+        this.left = left;
+        this.right = right;
+    }
+}