Create: 124-Binary-Tree-Maximum-Path-Sum.ts

javiermon · Sep 7, 2022 · c661398 · c661398
1 parent ac3cef1
commit c661398
Showing 1 changed file with 36 additions and 0 deletions.
diff --git a/typescript/124-Binary-Tree-Maximum-Path-Sum.ts b/typescript/124-Binary-Tree-Maximum-Path-Sum.ts
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+/**
+ * Definition for a binary tree node.
+ * class TreeNode {
+ * val: number
+ * left: TreeNode | null
+ * right: TreeNode | null
+ * constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
+ * this.val = (val===undefined ? 0 : val)
+ * this.left = (left===undefined ? null : left)
+ * this.right = (right===undefined ? null : right)
+ * }
+ * }
+ */
+
+function maxPathSum(root: TreeNode | null): number {
+ const res = [root.val];
+
+ // return max path sum without split
+ function dfs(root: TreeNode | null): number {
+ if (!root) {
+ return 0;
+ }
+
+ let leftMax = dfs(root.left);
+ let rightMax = dfs(root.right);
+ leftMax = Math.max(leftMax, 0);
+ rightMax = Math.max(rightMax, 0);
+
+ // compute max path sum WITH split
+ res[0] = Math.max(res[0], root.val + leftMax + rightMax);
+ return root.val + Math.max(leftMax, rightMax);
+ }
+
+ dfs(root);
+ return res[0];
+};