Amazon Interview Experience | 218 (On-Campus)

Hii, Everyone this is my interview experience with amazon.

***First Round (1:30 hr)-

It consist of two sections

:- Mcq (20 questions)

:- Two coding questions

1) Given two string Str1 and Str2, Find whether any anagram of Str2 is a sub-string of string Str1 (Case Insensitive) then return True otherwise False.
Test case :if Str1 = Amazon and Str2 = omaz, Output: True

2) Given n non-negative integers representing buildings where the width of each bar is 1, compute how much water it is able to trap after raining
For example,
Given [0,1,0,2,1,0,1,3,2,1,2,1], return 6.

I solved 19 mcq and both coding questions.

***Second Round (F2F):(1:30hr)

1) Find LCA in BST.

2) Find LCA in Binary Tree.

3) Given a binary tree where each node contains three pointers left,right,succ, where succ pointer is pointing to any of its successor node , the question is if any of succ pointer is pointing to its predecessor node then make that pointer NULL.
4) Given an array that represents the runs scored by a batsman and we have given the total score ,now we have to find out in how many ways can batsman score the run.

Ex – arr = {2,3,1} total run = 4

2+1+1 = 4, 3+1 = 4, 2+2 = 4, 1+3 = 4, 2+1+1 = 4 and many more.

First I have given the recursive solution than interview asked me dp solution, I told him DP approach he was satisfied.

5) Find Loop in a linked list and remove it.
6) You have 100 songs to play in a shuffling mode how will you play.

Interview want full working code for each question for last question he wanted only approach.

***Third Round (F2F):(1 hr)

1) Given a source string and a destination string and a dictionary consisting of various words write a program to find minimum length path to travel from source to destination. Rules for traversing:
1. You can only change one character at a time
2. Any resulting word has to be a valid word from dictionary
Example: Given source word CAT and destination word DOG , one of the valid sequence would be
CAT -> COT -> DOT -> DOG
Another valid sequence can be
CAT -> COT – > COG -> DOG

One character can change at one time and every resulting word has be a valid word from dictionary
I told him a approach using graph.

2) What is hashing.

3) What is modular hashing.

4) How collisions can be handled.

5) Is semphore guarantee deadlock prevention.

*** Fourth Round (F2F) : (2 hr)

1) A kind of celebrity problem you have n person where one of them is celebrity
condition are all non-celeb person knows celebrity and celebrity can know few other persons and all non- celeb persons can know few of them among each other so you have to find celebrity.

2) Given a binary tree and two nodes print the path between the two nodes of binary tree.

3) Find Height of Binary Tree represented by Parent array

All Practice Problems for Amazon !