SDE - 1

Given an array “A” of positive integers. Your task is to make the largest number possible formed by concatenating each of the array elements exactly once.
Example:
Let's say the given array is [ 9, 98, 7].

All the possible numbers formed by concatenating each of the array elements are 7989,7998,9879,9897,9987,9798. Among the six numbers, 9987 is the greatest number. Hence the answer is 9987.

Given an integer array ‘ARR’ of length ‘N’, return the number of longest increasing subsequences in it.
The longest increasing subsequence(LIS) is the longest subsequence of the given sequence such that all elements of the subsequence are in increasing order.
Note :
The subsequence should be a strictly increasing sequence.
For Example :
Let ‘ARR’ = [50, 3, 90, 60, 80].
In this array the longest increasing subsequences are [50, 60, 80] and [3, 60, 80]. There are other increasing subsequences as well but we need the number of longest ones. Hence the answer is 2.

You are given an array (ARR) of length N, consisting of integers. You have to find the sum of the subarray (including empty subarray) having maximum sum among all subarrays.
A subarray is a contiguous segment of an array. In other words, a subarray can be formed by removing 0 or more integers from the beginning, and 0 or more integers from the end of an array.
Note :
The sum of an empty subarray is 0.

You are given an array containing ‘N’ words. For each word, you need to find its shortest prefix which can uniquely identify it. For example “abcd” and “abdc” both have the prefix “ab” in common so we can’t uniquely find a word using the prefix “ab”. To uniquely identify both the words we need the prefix “abc” from “abcd” and “abd” from “abdc”.
Note:
You can assume that the words are unique. It means that it is always possible to find a unique prefix for each word.