Update 104-Maximum-Depth-of-Binary-Tree.java

orkhan-huseyn · orkhan-huseyn · commit 4c9fd50d1cf3 · 2022-12-25T19:37:03.000+04:00
diff --git a/java/104-Maximum-Depth-of-Binary-Tree.java b/java/104-Maximum-Depth-of-Binary-Tree.java
@@ -1,7 +1,27 @@
+// Recursive DFS
 class Solution {
-
     public int maxDepth(TreeNode root) {
         if (root == null) return 0;
         return 1 + Math.max(maxDepth(root.left), maxDepth(root.right));
     }
 }
+
+// BFS
+class Solution {
+    public int maxDepth(TreeNode root) {
+        if (root == null) return 0;
+        Queue<TreeNode> queue = new LinkedList<>();
+        queue.add(root);
+        int levels = 0;
+        while (!queue.isEmpty()) {
+            int size = queue.size();
+            for (int i = 0; i < size; i++) {
+                TreeNode current = queue.poll();
+                if (current.left != null) queue.add(current.left);
+                if (current.right != null) queue.add(current.right);
+            }
+            levels++;
+        }
+        return levels;
+    }
+}
