Get right side view of a binary tree

0199_binary-tree-right-side-view.cs

// O(N) Time , O(lg N) Space
public class Solution {
  IList<int> nodeList = null;
  
  public IList<int> RightSideView(TreeNode root) {
    nodeList = new List<int>();
    FindRight(root);
    return nodeList;
  }
  
  private void FindRight(TreeNode root, int depth = 0) {
    if (root == null)
      return ;
    
    if (nodeList.Count == depth)
      nodeList.Add(root.val);
    
    FindRight(root.right, depth + 1);
    FindRight(root.left, depth + 1);
  }
}