Amazon Interview | Set 118 (On-Campus for Internship)

The selection procedure consisted of an online round followed by two Personal Interviews.

Online Round:

The first round had 20 MCQs and two coding questions. The MCQs were based on the concepts from OS, DSA, compilers, architecture etc.

The coding questions were:

1. Given an array of positive and negative numbers, arrange them in an alternate fashion such that every positive number is followed by negative and vice-versa maintaining the order of appearance.

2. Given a n x m matrix, print the elements diagonal wise from top to bottom.

First round of PI :

1. Given a number n find the number of balanced parentheses expressions of that length.

Input: 2

Output: 1 which is (),

Input: 4

Output: 2 which are (()) and ()().

I gave a complex solution involving segment tree in which he pointed out the mistakes and then asked to write a code to check if a given expression is balanced or not.

2. Tell something about LRU. What DS will you use for it? Write pseudo code for it.

(Hint : Quite simple..Use doubly LL)

Second round of PI:

The interviewer introduced himself first and then asked me about myself.

We had a discussion on my projects.

1. Given two binary trees, write pseudo code to determine if one is a subtree of the other. I answered it and then he modified the question to check if the other tree elements are the subset of the elements of the first tree. (Hint: Inorder traversal)

2. Given a sorted circular linked list which is rotated at some point, write pseudo code to insert a new node. Ex: 8 1 2 5 7 and insert 6.

All Practice Problems for Amazon !