# Amazon Interview Experience : SDE : Set 31

Company Name: Amazon

Job Role: SDE

Years of Experience Required: Fresher (0 Yrs.)

Drive: Off-Campus (Referral)

## Preparation for Amazon

### Preparation

Topics: Data Structures and Algorithms

Duration: 1.5 years

Source of Preparation: Codechef,  Leetcode, GFG, Striver’s SDE sheet.

[BONUS]:

### Interview Rounds

Round 1: Online Coding Test

• Next greater permutation: Given an array Arr[] of integers, rearrange the numbers of the given array into the lexicographically next greater permutation of numbers. If such an arrangement is not possible, it must rearrange it as the lowest possible order (i.e., sorted in ascending order).
• The other question was based on binary search.

Round 2: Technical Interview

• Find Duplicate: Given an array of N + 1 size, where each element is between 1 and N. Assuming there is only one duplicate number, your task is to find the duplicate number.
• Given a string you need to print the size of the longest possible substring that has exactly K unique characters.

Round 3: Technical Interview

•  Trapping Rainwater: Given an array of non-negative integers representation elevation of ground. Your task is to find the water that can be trapped after rain.
• Given a Binary Tree of size N, where each node can have positive or negative values. Convert this to a tree where each node contains the sum of the left and right sub-trees of the original tree. The values of leaf nodes are changed to 0.

Round 4: Technical + Managerial

• Diff between multitasking and multiprocessing
• What happens when you enter “google.com”
• Delete a node in O(1): Write a function to delete a node in a singly-linked list. You will not be given access to the head of the list instead, you will be given access to the node to be deleted directly. It is guaranteed that the node to be deleted is not a tail node in the list.
• Rotate the given linked list by k places.

Verdict: Selected