Create 1373.二叉搜索子树的最大键值和.js

Author: yinxin630

1373.二叉搜索子树的最大键值和.js

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+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val) {
+ *     this.val = val;
+ *     this.left = this.right = null;
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number}
+ */
+var maxSumBST = function(root) {
+    let result = 0;
+    function dfs(node) {
+        if (!node) {
+            return 0;
+        }
+        const left = dfs(node.left);
+        const right = dfs(node.right);
+        if (left === null || right === null || (node.left && node.left.val >= node.val) || (node.right && node.right.val <= node.val)) {
+            return null;
+        }
+        const sum = left + right + node.val;
+        result = Math.max(result, sum);
+        return sum;
+    }
+    dfs(root);
+    return result;
+};
+
+console.log(maxSumBST(arrayToTree([5,4,8,3,null,6,3])));
+
+function arrayToTree(arr) {
+    function TreeNode(val) {
+        this.val = val;
+        this.left = this.right = null;
+    }
+    if (arr.length === 0) {
+        return null;
+    }
+    const root = new TreeNode(arr[0]);
+    const list = [root];
+    let i = 1;
+    while (list.length > 0) {
+        const node = list.shift();
+        if (typeof arr[i] === 'number') {
+            node.left = new TreeNode(arr[i]);
+            list.push(node.left);
+        }
+        i++;
+        if (typeof arr[i] === 'number') {
+            node.right = new TreeNode(arr[i]);
+            list.push(node.right);
+        }
+        i++;
+    }
+    return root;
+}