Find the Maximum Depth or Height of a Tree

Call the depth function recursively

1. if Sub tree/tree is empty then return 0

2. else get maximum depth in left sub tree and right sub tree + 1.

class Tree {

   int value;

   Tree left;

   Tree right;

   public Tree (int value) {

      this.value = value;

   }

}

public class FindMaxDepth {

   private static int depth(Tree tree) {

      if(tree==null) {

         return 0;

      } else {

         return Math.max(depth(tree.left), depth(tree.right)) + 1;

      }

   }

   public static void main(String[] args) {

      Tree root = new Tree(1);

      root.left = new Tree(2);

      root.right = new Tree(3);

      root.left.left = new Tree(7);

      root.left.right = new Tree(6);

      root.right.left = new Tree(5);

      root.right.right = new Tree(4);

      root.left.left.left = new Tree(8);

      root.left.left.right = new Tree(9);

      root.left.left.left.left = new Tree(11);

      root.left.left.left.right = new Tree(10);

      System.out.println(depth(root));

   }

}