Bottom Left item value in a binary tree

BottomLeft.java

package com.interviewbytes.trees;

import java.util.Deque;
import java.util.LinkedList;

public class BottomLeft {

    public int findBottomLeftValue(TreeNode root) {

        Deque<TreeNode> deque = new LinkedList<>();
        deque.offer(root);
        int leftBottom = -1;

        while (!deque.isEmpty()) {
            leftBottom = deque.peekFirst().val;
            int size = deque.size();
            while (size > 0) {
                TreeNode node = deque.poll();
                if (node.left != null) deque.offer(node.left);
                if (node.right != null) deque.offer(node.right);
                size--;
            }
        }

        return leftBottom;
    }
}

TreeNode.java

package com.interviewbytes.trees;

public class TreeNode {

    int val;
    TreeNode left;
    TreeNode right;

    TreeNode(int x) {
        val = x;
    }
}