Interview questions

Minimum Operations to Transform Array into Alternating Prime

Companies: Google

Array · Binary Search · Math · Number Theory

Minimum Possible Maximum Waiting Time

Companies: General Motors

Array · Dynamic Programming · Memoization

Minimum Removals to Balance Array

Given nums and k, remove the fewest elements so the remaining array has max ≤ k * min. Equivalently, find the largest subset of numbers…

Companies: Salesforce

Array · Binary Search · Sliding Window · Sorting

Minimum Replacements to Sort the Array

Given an integer array where you may replace any element with two positive integers summing to it, find the minimum number of such split operations…

Companies: Salesforce

Array · Greedy · Math

Minimum Subarray Length With Distinct Sum At Least K

Companies: Amazon

Array · Hash Table · Sliding Window

Minimum Sum of Squared Difference

Given two arrays and up to k1 and k2 unit +/-1 edits, minimize the sum of (nums1[i]-nums2[i])^2 by optimally allocating k = k1+k2 operations to…

Companies: Google

Array · Binary Search · Greedy · Heap (Priority Queue)

Minimum Swaps to Avoid Forbidden Values

Companies: Amazon

Array · Counting · Greedy · Hash Table

Minimum Total Cost to Process All Elements

Companies: Infosys

Array · Math · Simulation

Minimum XOR Path in a Grid

Companies: Google

Array · Bit Manipulation · Dynamic Programming · Matrix

Most Frequent IDs

Given a sequence of ID updates where each step adds or removes a given number of copies of an ID, maintain the dynamic multiset of…

Companies: Snowflake

Array · Hash Table · Heap (Priority Queue) · Ordered Set

Number of Flowers in Full Bloom

Given a list of closed time intervals for when each flower is in full bloom and query times for people arriving, return for each person…

Companies: Roblox

Array · Binary Search · Hash Table · Ordered Set

Number of Ways to Form a Target String Given a Dictionary

Count the number of ways to form target left-to-right by picking each target character from some word’s character at column k, with the constraint that…

Companies: Uber

Array · Dynamic Programming · String

Number of Ways to Wear Different Hats to Each Other

Count the number of ways to assign distinct hats (labels 1..40) to n ≤ 10 people given each person's allowed hat list, returning the answer…

Companies: Roblox

Array · Bipartite Graph · Bit Manipulation · Bitmask

Partition Array for Maximum Sum

Partition the array into contiguous subarrays of length at most k, replace every value in a subarray with that subarray's maximum, and maximize the resulting…

Companies: TikTok

Array · Dynamic Programming

Partition Array Into Two Arrays to Minimize Sum Difference

Partition the 2n integers into two equal-sized groups (choose n elements for one group) to minimize the absolute difference of their sums — a constrained…

Companies: Salesforce

Array · Binary Search · Bit Manipulation · Bitmask

Pascal's Triangle

Generate the first numRows of Pascal's Triangle as a list of lists, where each row starts and ends with 1 and every interior element equals…

Companies: Bloomberg

Array · Dynamic Programming

Power Update After K-th Largest Insertion I

Companies: Google

Array · Hash Table · Heap (Priority Queue) · Math

Put Marbles in Bags

Partition the array into k contiguous nonempty subarrays where each bag's cost is the sum of its endpoint weights, so the total score equals weights[0]+weights[n-1]…

Companies: Salesforce

Array · Greedy · Heap (Priority Queue) · Sorting

Queries on Number of Points Inside a Circle

Given a set of 2D integer points and multiple circular queries, compute for each circle how many points lie inside or on it; the main…

Companies: Anduril

Array · Geometry · Math

Rank Teams by Votes

Sort teams by aggregating position-wise vote counts: compare teams by their counts for first place, then second place, and so on, using alphabetical order as…

Companies: Atlassian

Array · Counting · Hash Table · Sorting

Read N Characters Given read4 II - Call Multiple Times

Implement a read(n) method using the provided read4(buf) API where read may be called multiple times; you must preserve and reuse leftover characters between calls…

Companies: Lyft, NVIDIA

Array · Interactive · Simulation

Remove Stones to Minimize the Total

Given an array of pile sizes and k operations each removing floor(pile/2) stones from a chosen pile (possibly the same pile multiple times), minimize the…

Companies: Salesforce

Array · Greedy · Heap (Priority Queue)