Find nodes in a binary tree which are at a distance K from a given node

You are given a binary tree and a node in the tree, your task is to find all the nodes in the binary tree which are at a distance K from that node. These nodes can be downwards [descendants of the node] or upwards.

For example: In this image

The nodes that are at a distance 2 from 7 are 5 (6’s left child), 11, 5 (2’s right child).

This is a coding question.

Function prototype:

void PrintKDistanceNode(Node *root, Node *node, int K)




Binary Search Tree in Binary Tree

Given a binary tree, find the largest binary SEARCH tree in this binary tree.

When I mean largest, the tree with maximum number of nodes. And the binary search tree should be a sub-tree in the given binary tree.

Note: Not every binary tree is a binary search tree 😛