Senior Software Engineer

Ninja Coin is a famous crypto-currency in Ninja Land. Ninja has an array/list ‘PRICE’ of size ’N’ where ‘PRICE[i]’ is the price of a Ninja Coin on an ith day in INR, where 0 <= 'i' <= N-1.

The span of the Ninja Coin price on an ith day is defined as the maximum number of consecutive days (starting from the ith day and going backward) for which the price of a Ninja Coin was less than or equal to its price at ith day.

Your task is to return an array/list of size ‘N’ where the ith integer is the span of Ninja Coin price on an ith day. Go through the example for more clarity.

For Example :

Let the price of Ninja Coin for 5 consecutive days is [4, 2, 3, 3, 7].

Then the span of Ninja Coin on the 0th day is 1 because we cannot move backward from day 0.

The span of Ninja Coin on the 1st day is 1 because the price on day 0 is 4 which is greater than 2, so the only day 1 is counted.

The span of Ninja Coin on the 2nd day is 2 because the price on day 2 and day 1 is less than or equal to 3 and then on day 0 price is 4 which is greater than 3, so we count day 2 and day 1.

The span of Ninja Coin on the 3rd day is 3 because the price on day 3, day 2, and day 1 is less than or equal to 3, and on day 0 price is 4 which is greater than 3, so we count day 3, day 2, and day 1.

The span of Ninja Coin on the 4th day is 5 because its value is higher than all previous days values.    

Thus you should return an array/list [1, 1, 2, 3, 5].

You are given an array ‘ARR’ of ‘N’ integers, you need to find the maximum length of the sub-array such that the product of elements of the sub-array is positive.

For Example:

Let us say we have array 'ARR' =[-1,3,5,-2,4,-9]. The longest sub-array with the positive product is [3,5,-2,4,-9]. 

Given a BST (Binary search tree) with N number of distinct nodes and two nodes ‘X’ and ‘Y’ (which are definitely present in the input BST). You need to find the value of the maximum node that lies in between the nodes ‘X’ and ‘Y’ (both inclusive) in the given BST.

A binary search tree (BST) is a binary tree data structure which has the following properties.

• The left subtree of a node contains only nodes with data less than the node’s data.
• The right subtree of a node contains only nodes with data greater than the node’s data.
• Both the left and right subtrees must also be binary search trees.

Note:

1. All the elements of the Binary Search Tree are unique.

2. You can’t use the same node value/element of BST twice.

You are given a string 'STR' consisting of lowercase English letters. Your task is to return all permutations of the given string in lexicographically increasing order.

String A is lexicographically less than string B, if either A is a prefix of B (and A ≠ B), or there exists such i (1 <= i <= min(|A|, |B|)), that A[i] < B[i], and for any j (1 <= j < i) A[i] = B[i]. Here |A| denotes the length of the string A.

For example :

If the string is “bca”, then its permutations in lexicographically increasing order are { “abc”, “acb”, “bac”, “bca”, “cab”, “cba” }.

Note:

Given string contains unique characters.

You are given a 2-dimensional array/list having N rows and M columns, which is filled with ones(1) and zeroes(0). 1 signifies land, and 0 signifies water.

A cell is said to be connected to another cell, if one cell lies immediately next to the other cell, in any of the eight directions (two vertical, two horizontal, and four diagonals).

A group of connected cells having value 1 is called an island. Your task is to find the number of such islands present in the matrix.

How does different application in OS can have single or multiple instance. How does one can configure it?

Give the LLD of a call centre call/query management service. Give class design, API contracts and business logic.