Minimum Depth of Binary Tree

use iterative 

import java.util.LinkedList;

import dataStructure.TreeNode;

public class MinimumDepthBinaryTree {

	public static void main(String[] args) {

		TreeNode t1 = new TreeNode(1);
		TreeNode t2 = new TreeNode(2);
		TreeNode t3 = new TreeNode(3);
		TreeNode t4 = new TreeNode(4);
		TreeNode t5 = new TreeNode(5);
		TreeNode t6 = new TreeNode(6);
		TreeNode t7 = new TreeNode(7);
		TreeNode t8 = new TreeNode(8);
		TreeNode t9 = new TreeNode(9);
		TreeNode t10 = new TreeNode(10);
		TreeNode t11 = new TreeNode(11);
		TreeNode t12 = new TreeNode(12);
		TreeNode t13 = new TreeNode(13);
		TreeNode t14 = new TreeNode(14);
		t1.left = t2;
		t1.right = t3;
		t2.left = t4;
		t2.right = t5;
		t3.right = t6;
		t4.right = t7;
		t4.left = t8;
		t6.left = t9;
		t9.left = t10;
		t10.left = t11;
		t11.right = t12;
		t12.left = t13;
		t12.right = t14;
		minDepth(t1);
	}

	public static int minDepth(TreeNode root) {
        if(root == null){
            return 0;
        }
 
        LinkedList<TreeNode> nodes = new LinkedList<TreeNode>();
        LinkedList<Integer> counts = new LinkedList<Integer>();
 
        nodes.add(root);
        counts.add(1);
 
        while(!nodes.isEmpty()){
            TreeNode curr = nodes.remove();
            int count = counts.remove();
 
            if(curr.left == null && curr.right == null){
                return count;
            }
 
            if(curr.left != null){
                nodes.add(curr.left);
                counts.add(count+1);
            }
 
            if(curr.right != null){
                nodes.add(curr.right);
                counts.add(count+1);
            }
        }
 
        return 0;
    }
}