solve maximum-depth-of-binary-tree

Author: 1lsang

maximum-depth-of-binary-tree/1lsang.ts

@@ -0,0 +1,35 @@
+/**
+ * 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 maxDepth(root: TreeNode | null): number {
+  // DFS (혹은 BFS) 후 깊이 체크하기
+  if (!root) return 0;
+  
+  const stack: [TreeNode, number][] = [[root, 1]];
+  let maxDepth = 0;
+
+  while (stack.length > 0) {
+    const [node, depth] = stack.pop()!;
+    maxDepth = Math.max(maxDepth, depth);
+
+    if (node.right) {
+      stack.push([node.right, depth + 1]);
+    }
+    if (node.left) {
+      stack.push([node.left, depth + 1]);
+    }
+  }
+
+  return maxDepth;
+};