Software Developer

You are given an array ‘prices’ of a stock and a number ‘amount’. Each element of the array/list prices, ‘prices[i]’ represent the price of the stock on the ‘i-th’ day. Your task is to buy the maximum number of stocks in ‘amount’ money. Every stock has an infinite supply.

Rule to buy a stock: On the ‘i-th’ day you can buy at max ‘i’ a number of stock and ‘i’ is ‘1’ based.

For example: Given ‘prices = {10, 7, 19}’, and ‘amount = 45’.

Buy 1- stock on the first day, 2-stocks on the second day, and 1-stock on the third day, so the total investment amount is ‘1 * 10 + 2 * 7 + 1 * 19 = 10 + 14+ 19 = 43’ so you can buy ‘4’ stock in ‘amount =45’.

You are given an array Arr consisting of n integers, you need to find all the distinct triplets present in the array which adds up to zero.

An array is said to have a triplet {arr[i], arr[j], arr[k]} with 0 sum if there exists three indices i, j and k such that i!=j, j!=k and i!=k and arr[i] + arr[j] + arr[k] = 0.

Note :

1. You can return the list of values in any order. For example, if a valid triplet is {1, 2, -3}, then (2, -3, 1), (-3, 2, 1) etc is also valid triplet. Also, the ordering of different triplets can be random i.e if there are more than one valid triplets, you can return them in any order.
2. The elements in the array need not be distinct.
3. If no such triplet is present in the array, then return an empty list, and the output printed for such a test case will be "-1".

System design - WhatsApp
Functional requirements- send and receive msg
Following things are expected
Block diagram
Database schema
Database queries - optimized

Design IRCTC, searching module
Functional requirements
Fast search
Constraints
100000 training are there in the system
1000000 station are there in the system
A train can have maximum 400 stops
Write block diagram, decide database schema and how you store the trains and station information