CountCompleteTreeNodez.java

package com.learning.leet.tree;

/**
 * Created by sargonbenjamin on 7/10/19.
 * https://leetcode.com/problems/count-complete-tree-nodes/
 */
public class CountCompleteTreeNodez {
    public int countNodes(TreeNode root) {
        if(root==null)return 0;
        int leftMost = nodeDepthLeft(root);
        int rightMost = nodeDepthRight(root);
        if(leftMost==rightMost)return (int)Math.pow(2,leftMost) -1;
        return countNodes(root.left) + countNodes(root.right) + 1;
    }

    public int nodeDepthLeft(TreeNode root){
        if(root==null)return 0;
        return 1 + nodeDepthLeft(root.left);
    }

    public int nodeDepthRight(TreeNode root){
        if(root==null)return 0;
        return 1 + nodeDepthLeft(root.right);
    }
}