Created 543-Diameter-of-Binary-Tree

typescript/543-Diameter-of-Binary-Tree.ts

@@ -0,0 +1,30 @@
+/**
+ * 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 diameterOfBinaryTree(root: TreeNode | null): number {
+ let res = [0];
+
+ function dfs(root: TreeNode | null): number {
+ if (!root) return -1;
+ let left = dfs(root.left);
+ let right = dfs(root.right);
+
+ res[0] = Math.max(res[0], 2 + left + right);
+
+ return 1 + Math.max(left, right);
+ }
+
+ dfs(root);
+ return res[0];
+}