Binary Tree Level Order Traversal / 중급

Author: oh-chaeyeon

oh-chaeyeon/5주차_트리/Binary_Tree_Level_Order_Traversal.js

@@ -0,0 +1,26 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number[][]}
+ */
+var levelOrder = function (root) {
+  const result = [];
+
+  function traverse(node, level) {
+    if (!node) return;
+    if (!result[level]) result[level] = [];
+    result[level].push(node.val);
+    traverse(node.left, level + 1);
+    traverse(node.right, level + 1);
+  }
+
+  traverse(root, 0);
+  return result;
+};