Create 0103-binary-tree-zigzag-level-order-traversal.js

Author: aadil42

Diff for: javascript/0103-binary-tree-zigzag-level-order-traversal.js

@@ -0,0 +1,49 @@
+/**
+ * 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)
+ * }
+ */
+/**
+ * BFS | LevelOrderTraversal
+ * Time O(n) | Space O(n)
+ * https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/
+ * @param {TreeNode} root
+ * @return {number[][]}
+ */
+var zigzagLevelOrder = function(root) {
+    
+    const q = new Queue();
+
+    if(root) q.enqueue(root);
+
+    let isLeft = true;
+
+    const zigzagOrder = [];
+
+    while(!q.isEmpty()) {
+
+        let size = q.size();
+        const row = [];
+
+        while(size) {
+            const node = q.dequeue();
+            row.push(node.val);
+            if(node.left) q.enqueue(node.left);
+            if(node.right) q.enqueue(node.right);
+            size--;
+        }
+        
+        if(!isLeft) {
+            zigzagOrder.push(row.reverse());
+        }
+        if(isLeft) {
+            zigzagOrder.push(row);
+        }
+        isLeft = !isLeft;
+    }
+
+    return zigzagOrder;
+};