Cousins In Binary Tree

How to check if two nodes are cousins in a Binary tree.

Given two values x and y, we have to write a code to check the nodes corresponding to values x and y are cousins or not. All the values in this binary tree are unique.

Two nodes of a binary tree are cousins if they have the same depth, but have different parents.

In a binary tree, the root node is at depth 0, and children of each depth k node are at depth k+1.

Last Stone Weight

Given a collection of stones, each stone has a positive integer weight. Each turn, we choose the two heaviest stones and smash them together.

Suppose the stones have weights x and y with x <= y.  The result of this smash is:

If x == y, both stones are totally destroyed.

If x != y, the stone of weight x is totally destroyed, and the stone of weight y has new weight y-x.

At the end, there is at most 1 stone left.  Return the weight of this stone (or 0 if there are no stones left.)

For Example –

Input: {2, 7, 4, 1, 8, 1}, Output: 1

Explanation: 

We combine 7 and 8 to get 1 so the array converts to {2, 4, 1, 1, 1} then,

we combine 2 and 4 to get 2 so the array converts to {2, 1, 1, 1} then,

we combine 2 and 1 to get 1 so the array converts to {1, 1, 1} then,

we combine 1 and 1 to get 0 so the array converts to {1} then that’s the value of last stone.