package tree;

/**

* Created by gouthamvidyapradhan on 30/08/2017. Given a binary tree, find the leftmost value in the

* last row of the tree.

*

* <p>Example 1: Input:

*

* <p>2 / \ 1 3

*

* <p>Output: 1 Example 2: Input:

*

* <p>1 / \ 2 3 / / \ 4 5 6 / 7

*

* <p>Output: 7 Note: You may assume the tree (i.e., the given root node) is not NULL.

*/

public class FindBottomLeftTreeValue {

private int max = 0, result;

public static class TreeNode {

int val;

TreeNode left;

TreeNode right;

TreeNode(int x) {

val = x;

}

}

public static void main(String[] args) throws Exception {

TreeNode root = new TreeNode(1);

root.left = new TreeNode(2);

root.left.left = new TreeNode(4);

root.right = new TreeNode(3);

root.right.left = new TreeNode(5);

root.right.left.left = new TreeNode(7);

root.right.right = new TreeNode(6);

System.out.println(new FindBottomLeftTreeValue().findBottomLeftValue(root));

}

public int findBottomLeftValue(TreeNode root) {

preorder(root, 1);

return result;

}

private void preorder(TreeNode node, int level) {

if (node != null) {

if (level > max) {

result = node.val;

max = level;

}

preorder(node.left, level + 1);

preorder(node.right, level + 1);

}

}

}