[移动开发]二叉树层序遍历（swift）

public class TreeNode {
     public var val: Int
     public var left: TreeNode?
     public var right: TreeNode?
     public init() { self.val = 0; self.left = nil; self.right = nil; }
     public init(_ val: Int) { self.val = val; self.left = nil; self.right = nil; }
     public init(_ val: Int, _ left: TreeNode?, _ right: TreeNode?) {
         self.val = val
         self.left = left
         self.right = right
     }
 }

class Solution {
    func levelOrder(_ root: TreeNode?) -> [[Int]] {
        
        var someInts = [[Int]]()
        if let node = root{
         var arr =  [node]
            while arr.count > 0 {
                var tmpNods = [TreeNode]()
                var tmp = [Int]()
                for node in arr {
                    tmp.append(node.val)
                    if let left = node.left{
                        tmpNods.append(left)
                    }
                    if let right = node.right{
                        tmpNods.append(right);
                    }
                }
                arr = tmpNods
                someInts.append(tmp)
            }
            
        }
        return someInts
    }
}