Create 102-Binary-Tree-Level-Order-Traversal.swift

Author: Dmitriy Buzulutskiy

swift/102-Binary-Tree-Level-Order-Traversal.swift

@@ -0,0 +1,28 @@
+class Solution {
+    func levelOrder(_ root: TreeNode?) -> [[Int]] {
+        guard let root = root else { return [] }
+        var queue = [TreeNode]()
+        var result = [[Int]]()
+        queue.append(root)
+        while !queue.isEmpty {
+            var levelCount = queue.count
+            var levelNodes = [Int]()
+            while levelCount > 0 {
+                let node = queue.first!
+                queue.removeFirst()
+                levelCount -= 1
+                levelNodes.append(node.val)
+                if let left = node.left {
+                    queue.append(left)
+                }
+
+                if let right = node.right {
+                    queue.append(right)
+                }
+            }
+            result.append(levelNodes)
+        }
+        return result
+    }
+
+}