Software Engineer

Ninja is fond of sequences. He has a set of numbers and wants to make minimum decreasing subsequences such that all numbers are part of exactly one subsequence. Can you help Ninja with this challenge?

You are given an array ‘ARR’ having ‘N’ elements.Your task is to divide all ‘N’ elements of the array into a minimum number of strictly decreasing subsequences. Each number can be in one subsequence only. Find the minimum number of such strictly decreasing subsequences.

For Example

If 'ARR' is [4,2,1,3] ,it can be splitted into two subsequences as [4,2,1] , [3] or [4,3],[2,1].  

You are given an array “arr'' of integers. Your task is to find the contiguous subarray within the array which has the largest product of its elements. You have to report this maximum product.

An array c is a subarray of array d if c can be obtained from d by deletion of several elements from the beginning and several elements from the end.

For e.g.- The non-empty subarrays of an array [1,2,3] will be- [1],[2],[3],[1,2],[2,3],[1,2,3]. 

For Example:

If arr = {-3,4,5}.
All the possible non-empty contiguous subarrays of “arr” are {-3}, {4}, {5}, {-3,4}, {4,5} and {-3,4,5}.
The product of these subarrays are -3, 4, 5, -12, 20 and -60 respectively.
The maximum product is 20. Hence, the answer is 20.

Follow Up:

Can you solve this in linear time and constant space complexity?

A palindrome string is one that reads the same backward as well as forward.

You are given a string 'str'.

Find the minimum number of characters needed to insert in 'str' to make it a palindromic string.

Example :

Input: 'str' = "abca"

Output: 1

Explanation:
If we insert the character ‘b’ after ‘c’, we get the string "abcba", which is a palindromic string. Please note that there are also other ways possible.

You are given a matrix of flight 'TICKETS', where the 'i'th row represents 'i’th flight ticket. 'TICKETS'[i] = [SOURCE, DESTINATION] represents that there is a one-way flight starting from the city 'SOURCE' and ending at city 'DESTINATION'. All the flight tickets belong to a man who is initially in city "DEL".

You are supposed to reconstruct the journey satisfying the following conditions:

1. He should begin his journey from “DEL”.

2. He should use all the tickets and complete the journey.

3. He must use all the tickets only once.

Note:

1. Journey means the order in which the cities will be visited.

2. The given tickets have at least one itinerary.

3. If multiple valid itineraries are possible, then return the itinerary that is a lexicographically smallest itinerary.

You are given an Integer array ‘ARR’ and an Integer ‘K’.

Your task is to find the ‘K’ most frequent elements in ‘ARR’. Return the elements in any order.

For Example:

You are given ‘ARR’ = {1, 2, 2, 3, 3} and ‘K’ = 2. 

The answer will {2, 3} as 2 and 3 are the elements occurring most times.