SDE - Intern

A Ninja was learning how to calculate the binomial coefficient. But, learning that alone won’t help the ninja since a lot of problems are required to be solved as homework. Since the ninja is old-fashioned and doesn’t know that a computer can do the same homework in a matter of a few seconds you will have to help with the problems.

You need to complete a function for the ninja that can calculate the binomial of a number where when given two integers 'N' and 'R', the program can calculate its respective binomial coefficient nCr. Since the answer may be very large, calculate the answer modulo 10^9 + 7.

For Example:

Input: 'N' = 5, 'R' = 2
Output: 10

The value of 5C2 is 10
After taking the modulo with 10^9 + 7 we get 10.

You have been given a Binary Tree of integers. You are supposed to return the largest subtree sum in the given Binary Tree.

The subtree sum of a node is defined as the sum of all the node values formed by the subtree rooted at that node (including the node itself).

Example :

For the given binary tree:

Subtree with the largest sum is highlighted in the above image. The sum is (-2 + 4 + 7) = 9

You are given a tree(root 0) with N vertex having N - 1 edges. You are also given an array ‘QUERY’ of size ‘Q’, where each query consists of an integer that denotes a node. You have to print the xor of all the values of nodes in the sub-tree of the given node.

Note:

Here XOR denotes the bitwise operator (^).

You have been given a grid containing some oranges. Each cell of this grid has one of the three integers values:

Value 0 - representing an empty cell.

Value 1 - representing a fresh orange.

Value 2 - representing a rotten orange.

Every second, any fresh orange that is adjacent(4-directionally) to a rotten orange becomes rotten.

Your task is to find out the minimum time after which no cell has a fresh orange. If it's impossible to rot all the fresh oranges then print -1.

Note:

1. The grid has 0-based indexing.
2. A rotten orange can affect the adjacent oranges 4 directionally i.e. Up, Down, Left, Right.

You have been given 'N' ropes of different lengths, we need to connect these ropes into one rope. The cost to connect two ropes is equal to sum of their lengths. We need to connect the ropes with minimum cost.

The test-data is such that the result will fit into a 32-bit integer.

Given an array/list of integers of length ‘N’, there is a sliding window of size ‘K’ which moves from the beginning of the array, to the very end. You can only see the ‘K’ numbers in a particular window at a time. For each of the 'N'-'K'+1 different windows thus formed, you are supposed to return the maximum element in each of them, from the given array/list.