Amazon DS & Algo Round Interview Questions Asked In 2026

Max Words Visible on Scrollable Screen

Write an implementation for a method that returns the maximum number of complete words visible on the screen at any time while writing all words.

Assign Aggressive Cows To Stalls

A farmer has a long barn containing N stalls.

Each stall is placed on a straight line, and the position of every stall is represented by an integer coordinate.

The farmer needs to place C cows into these stalls.

Since the cows become aggressive when they are too close to one another, the farmer wants to place them in such a way that the closest pair of cows is as far apart as possible.

Your task is to return the maximum possible value of the minimum distance between any two placed cows.

Trim Tree To Complete Binary Tree

The tree may not be a complete binary tree.

Your task is to choose a largest possible complete binary tree from the given tree by trimming away nodes that are not part of the chosen complete tree.

Two Sum Closest To And Less Than Target

You are given a list of integers numbers and an integer target.

Your task is to choose two different elements from the list such that their sum is as large as possible while still being strictly less than target.

Search Minimum And Rotation Count In Rotated Sorted Array

You are given a rotated sorted list of integers.

A sorted list is rotated when some prefix of the list is moved to the end while preserving the relative order of all elements.

For example, the sorted list [1, 2, 3, 4, 5, 6, 7] can become [4, 5, 6, 7, 1, 2, 3] after rotation.

Your task is to support searching and rotation analysis on this rotated sorted list.

Use Path Operations To Minimize Tree Diameter

Maximum Power Assigned To Machines

Minimum Cost to Join Sticks

You are given a list of sticks, where each stick has a positive integer length.

You may repeatedly choose any two sticks and join them into one new stick. If the chosen sticks have lengths x and y, then the new stick has length x + y, and the cost paid for this operation is also x + y.

You must continue joining sticks until exactly one stick remains.

Your task is to return the minimum total cost required to join all sticks into one stick.

Longest Subarray Sum Equals Zero

numbers, and zero.

A subarray is a contiguous part of the list.

Your task is to find the maximum length of any subarray whose sum is exactly 0.

Find Kth Largest Element From Chef's Collection

Chef maintains a changing collection of integer values, such as scores, ranks, or performance numbers.

At any point, Chef may be asked to find the current k-th largest value in the collection. Unlike a version where k is fixed, here k can be different for different queries.

Your task is to support insert operations and find operations on this dynamic collection.

Fill Grid Based on Crop Frequency

Maximum Stones Path Sum

Given a grid of stone values, find the maximum total number of stones that can be collected while moving from the bottom-left cell to the top-right cell.

Minimum Meeting Rooms Required

You are given a list of meeting time intervals. Your task is to determine the minimum number of meeting rooms required so that no two overlapping meetings are placed in the same meeting room.

Passenger Count During Car Trips

Alien Language Letter Order

A new alien language uses lowercase Latin letters, but the order of the letters is not known.

You are given a list of non-empty dictionary words. The words are already sorted in lexicographical order according to the rules of this alien language.

Your task is to derive the lexicographically smallest valid ordering of letters in the alien language.

Design Google Like Search Autocomplete System

Count Connected Groups in Undirected Graph

You are given nodeCount nodes labeled from 0 to nodeCount - 1.

You are also given a list of undirected edges. Each edge is provided as a string in links, and each string contains two node labels separated by a comma.

Your task is to count how many separate connected groups, also called connected components, exist in the undirected graph.

Verify Undirected Graph Valid Tree

You are given n nodes labeled from 0 to n - 1.

You are also given a list of undirected connections between nodes. Each connection is provided as a string in connections, and each string contains two node labels separated by a comma.

Your task is to determine whether these connections form a valid tree.

Design Stack With Peek And Pop Maximum Element

Design a MaxStack data structure that works like a normal stack and also supports retrieving and removing the current maximum value.

The stack must support adding values, removing the top value, reading the top value, reading the maximum value, and removing the maximum value.

Design Logger System With Message Timestamps

Design a Logger system that receives a stream of messages with timestamps.

Each message should be printed only if the same message was not printed during the previous 10 seconds.

Given a timestamp and a message, return true if the message should be printed at that timestamp. Otherwise, return false.

Employee Schedule Common Free Time

You are given the work schedule of multiple employees.

Each employee has one or more working time intervals. For every employee, the intervals are non-overlapping and sorted by start time.

Your task is to return all finite intervals where every employee is free at the same time.

Find Missing Numbers In Range

You are given a sorted list of unique integers nums and two integers lower and upper.

The range from lower to upper, inclusive, contains all valid numbers that should be considered.

Your task is to find every number in this inclusive range that does not appear in nums.

Count Distinct Islands In Grid

You are given a non-empty grid containing only 0 and 1.

Each 1 represents land, and each 0 represents water.

An island is a connected group of land cells. Two land cells are connected if they share a side horizontally or vertically.

Your task is to count how many distinct island shapes exist in the grid.

Calculator To Evaluate Simple Expression String

Implement a basic calculator that evaluates a valid arithmetic expression given as a string.

The expression may contain non-negative integers, the operators +, -, *, and /, opening parentheses (, closing parentheses ), and empty spaces.

Design Tic Tac Toe Game

Create a class named TicTacGame that manages a Tic-tac-toe game played by two players on an m x m board.

Insert Into Circular Linked List While Keeping It Sorted

Use Robot To Clean Every Reachable Empty Cell In Room

You are given a robot placed inside a room that must clean every empty cell it can reach.

The room is represented as an m x n grid. A value of 1 represents an empty cell that can be visited and cleaned, while a value of 0 represents a wall that blocks movement.

The robot can move only in four directions: up, right, down, and left.

Your task is to find how many reachable empty cells the robot can clean

Multiply Sparse Matrices

You are given two sparse integer matrices A and B.

Return the matrix product A * B.

Longest Substring With At Most Two Distinct Characters

You are given a string s.

Return the length of the longest substring of s that contains at most two distinct characters.

Longest Substring With At Most N Distinct Characters

You are given a string s and an integer n.

Return the length of the longest substring of s that contains at most n distinct characters.

Find Anagram Index Mapping

You are given two integer lists A and B of the same length.

List B is an anagram of list A, which means B contains exactly the same elements as A, but possibly in a different order.

Return an index mapping list P from A to B.

Design System To Store Logs With Timestamp

Design a log storage system that stores logs using a unique integer id and a timestamp.

Each timestamp is a string in the format Year:Month:Day:Hour:Minute:Second.

Maximum Enemies Killed By One Bomb

Next Larger Palindrome Using Same Digits

You are given a numeric string num.

The string num represents a very large palindrome.

Return the smallest palindrome that is strictly larger than num and can be formed by rearranging exactly the same digits.

Design Snake Game With Food And Score

Generate Palindromic Permutations Of String

You are given a string s.

Return all distinct permutations of s that are palindromes.

Shortest Word Distance Between Words

Design a class that is initialized with a list of words.

After initialization, the class must support repeated queries asking for the shortest distance between two different words in the original list.

The distance between two words is the absolute difference between their indices in the list.

Find Celebrity At Party