Added maximum depth of bt solution

Author: nhistory

maximum-depth-of-binary-tree/nhistory.js

@@ -0,0 +1,46 @@
+/**
+ * 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 maxDepth = function (root) {
+  // Check root is null or not
+  if (root === null) {
+    return 0;
+  }
+  // Make queue array to store root and depth variable
+  let queue = [root];
+  let depth = 0;
+  // Iterate until there is an element inside of queue
+  while (queue.length > 0) {
+    // Record level size to avoid fault size measuring
+    let levelSize = queue.length;
+
+    for (let i = 0; i < levelSize; i++) {
+      // Grasp first element from the queue
+      const node = queue.shift();
+      // Push the left node into the queue
+      if (node.left) {
+        queue.push(node.left);
+      }
+      // Push the right node into the queue
+      if (node.right) {
+        queue.push(node.right);
+      }
+    }
+    // Increase depth value
+    depth++;
+  }
+
+  return depth;
+};
+
+// TC: O(n)
+// SC: O(n)