Given a Binary Tree and a positive integer k, count all distinct nodes that are distance k from a leaf node. Here k distance from a leaf means k levels higher than a leaf node. For example if k is more than height of Binary Tree, then nothing should be counted. Expected time complexity is O(n) where n is the number nodes in the given Binary Tree.
The first line of input contains an integer T denoting the number of test cases. Then T test cases follow. Each test case contains an integer n denoting the number of edges. The next line contains edges of the binary tree. The last line contains the value of k.
Count the distinct number of nodes that are at distance k from the lead nodes.
1<=data of node<=100
1 2 L 2 4 R 2 5 R 1 3 R 3 6 L 6 8 R 3 7 R
1 3 L 3 5 L 5 7 L 5 8 R 8 9 R