import java.util.*;

  • public class TreeNode {
  • int val = 0;
  • TreeNode left = null;
  • TreeNode right = null;
  • }

public class Solution {

public int maxDepth (TreeNode root) {
    // write code here
    if (root == null){
        return 0;
    }
    int lDepth = maxDepth(root.left);
    int rDepth = maxDepth(root.right);
    return 1 + Math.max(lDepth,rDepth);
}

}