kk

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

@@ -0,0 +1,4 @@
+package com.dota.common;
+
+public class Tree {
+}

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

@@ -0,0 +1,20 @@
+package com.dota.common;
+
+public class TreeNode {
+	public int val;
+	public TreeNode left;
+	public 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;
+	}
+}

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

@@ -0,0 +1,24 @@
+package com.dota.tree;
+
+import com.dota.common.TreeNode;
+
+// 1038. 从二叉搜索树到更大和树
+public class Solution {
+	int sum = 0;
+
+	public TreeNode bstToGst(TreeNode root) {
+		dfs(root);
+		return root;
+	}
+
+	void dfs(TreeNode node) {
+		if (node == null) {
+			return;
+		}
+
+		dfs(node.right);
+		sum += node.val;
+		node.val = sum;
+		dfs(node.left);
+	}
+}