week4: maximum-subarray

reeseo3o · reeseo3o · commit 68408c98da18 · 2026-03-28T18:37:38.000+09:00
diff --git a/maximum-subarray/reeseo3o.js b/maximum-subarray/reeseo3o.js
@@ -0,0 +1,34 @@
+/**
+ * Time complexity: O(n)
+ * Space complexity: O(h) - h is the height of the tree, worst case O(n)
+ */
+const maxDepth = (root) => {
+  if (root === null) return 0;
+
+  const leftDepth = maxDepth(root.left);
+  const rightDepth = maxDepth(root.right);
+
+  return 1 + Math.max(leftDepth, rightDepth);
+};
+
+// BFS - TC: O(n) | SC: O(n)
+const maxDepthBFS = (root) => {
+  if (root === null) return 0;
+
+  const queue = [root];
+  let depth = 0;
+
+  while (queue.length > 0) {
+    const levelSize = queue.length;
+
+    for (let i = 0; i < levelSize; i++) {
+      const node = queue.shift();
+      if (node.left) queue.push(node.left);
+      if (node.right) queue.push(node.right);
+    }
+
+    depth++;
+  }
+
+  return depth;
+};
