public static void Helper(LeetCode102TreeNode root, int level) { if (root == null) { return; } if (level == ans.Count) { ans.Add(new List <int>()); } ans[level].Add(root.val); if (root.left != null) { Helper(root.left, level + 1); } if (root.right != null) { Helper(root.right, level + 1); } }
public static IList <IList <int> > LevelOrder(LeetCode102TreeNode root) { Helper(root, 0); return(ans); }
public LeetCode102TreeNode(int val = 0, LeetCode102TreeNode left = null, LeetCode102TreeNode right = null) { this.val = val; this.left = left; this.right = right; }