# Internship Interview Experience at DE Shaw

Recently, DE SHAW conducted it’s internship recruitment drive at NSIT. We congratulate **Kush Mishra** , for successfully clearing all the rounds and thank him for sharing his interview experience with us. Here are the questions he was asked in the interview.

**PRELIMINARY ROUND**

1) There are certain amount of candies in a box . Person A will pick randomly n different andies (by different we mean that if candy1 of orange color is picked then candy1 of orange color cannot be picked but candy2 of orange color can be picked). And for each candy Person A picks he will tell the no. of candies available in the box of that type. We have to tell the minimum possible candies in the box.

Example n = 4 2 2 3 1

2) The first picked candy belong to that type of cany which has 2 candy in number. Second picked candy is also from the type which has 2 candies in number so they both can belong to same group ,, like first picked candy is candy1 of type1 and 2nd picked is candy2 of type 1. next we pick a candy whose type has 3 candies. And the 4th candy has only one candy of its type. Therefore m iimum number of candies are 2+3+1=6.

Given a binary string find the longest substring which contails 1’s more than 0’s. Eaxmple 1010 Ans = 3 as substring of string 3 is 101 which has 1 occuring more number of times than 0.

**ROUND 1**

1) Given time in HH:MM format … find the angle between the hour and minute hand?

2) Given a string find the minimum number of insertions to make it a palindrome.

3) Given a string find the minimum number of displacements of characters to make it palindrome. Ex cct : one displacement that is c to the right of t makes it ctc which is a palindrome.

4) Find the 4th element from the end of a LL.

**ROUND 2**

1) Given an array containing 1 to n elements .. find the occurance of each number in the array without using extra space and o(n) time

2) Find the number of BSTs which can be made given n nodes

3) Given an array containing integers , find the number of ways a number k can be made using those integers . Integers can be used infinite number of times.

4) Project discussion ! Nodejs,angular and typescript

**ROUND 3**

Normal questions such as hobbies and passions and future goals. Some discussion about the background etc.

Do leave your comments, or requests if you want some tutorial on any of these questions. We will be happy to help.

Keep Learning ! Coding Blocks Team