SDE - 1

Main questions that were asked were based on callbacks, promises, Closures, Event loop.
Some output guessing questions :
1. Difference between let, var, const
2. ES6 features
3. Hoisting
4. Rest, spread operator and other basic concepts of JavaScript

Questions related to my project were asked.
I had made a carpool app as my internship project in React Native, Node.js and Mongo DB.
So mainly questions were from them.
1. SQL vs NoSQL
2. Event loop
3. Synchronous vs Asynchronous

 

Given an array ARR of N integers and an integer S. The task is to find whether there exists a subarray(positive length) of the given array such that the sum of elements of the subarray equals to S or not. If any subarray is found, return the start and end index (0 based index) of the subarray. Otherwise, consider both the START and END indexes as -1.

Note:

If two or more such subarrays exist, return any subarray.

For Example: If the given array is [1,2,3,4] and the value of S is equal to 7. Then there are two possible subarrays having sums equal to S are [1,2,3] and [3,4].

You have been given two arrays, 'AT' and 'DT', representing the arrival and departure times of all trains that reach a railway station.

Your task is to find the minimum number of platforms required for the railway station so that no train needs to wait.

Note :

1. Every train will depart on the same day and the departure time will always be greater than the arrival time. For example, A train with arrival time 2240 and departure time 1930 is not possible.

2. Time will be given in 24H format and colons will be omitted for convenience. For example, 9:05AM will be given as "905", or 9:10PM will be given as "2110".

3. Also, there will be no leading zeroes in the given times. For example, 12:10AM will be given as “10” and not as “0010”.

He asked me some output questions which were based on JavaScript fundamentals like hoisting, arrow function etc.
Some questions were from Redux. At that time I didn't have any experience in Redux so I told him the same.

He asked me some JavaScript questions again and also told me about the work culture of his team. It was more like an open discussion with some tech questions

Some general HR questions.
1. Why paytm
2. Expected salary
3. Last drawn salary ( if applicable )