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CodeSignal OAs Interview Questions

30 practice questions for CodeSignal OAs technical interviews

coding Hard Verified

OA[CodeSignal] Cloud File Storage System


Category: Graph coding problem
# Question Your task is to implement a simple in-memory cloud storage system that maps objects (files) to their metadata (name, size, etc.). You...
Input: Graph (nodes and edges)
Output: Array
coding Hard Verified

OA[CodeSignal] Design Banking System


Category: Graph coding problem
# Question Design a banking system that supports account management, transactions, and various financial operations.
Input: Graph (nodes and edges)
Output: Computed result
coding Hard Verified

OA[CodeSignal] In-Memory Database


Category: Graph coding problem
# Description Implement a simplified in-memory database that supports record manipulation with various operations. The system should handle basic...
Input: Graph (nodes and edges)
Output: Array
coding Hard Verified

OA[CodeSignal] Employee Management System


Category: Graph coding problem
You are tasked with designing an employee management system that tracks work sessions, calculates work hours, handles promotions, and manages salary...
Input: Graph (nodes and edges)
Output: Computed result
coding Medium Verified

OA[CodeSignal] Find Effective Communication Channels


Category: String coding problem
You are given billing records, communication logs, and payment records for a healthcare system. Your task is to determine which communication channel...
Input: String
Output: Computed result
coding Hard Verified

OA [CodeSignal] Adventure Levels


Category: Array coding problem
# OA [CodeSignal] Adventure Levels You start with initial energy K. You need to clear a series of adventure levels. For each level i: -...
Input: Array
Output: Array
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OA [CodeSignal] Balanced Numbers in Permutation


Category: Array coding problem
# OA [CodeSignal] Balanced Numbers in Permutation Given a permutation p of integers from 1 to n. A number k (where 1 <= k <= n) is called...
Input: Array
Output: Computed result
coding Hard Verified

OA [CodeSignal] Count Palindrome Paths in Tree


Category: Tree coding problem
Given a tree with n nodes where each node has a lowercase English character c[i]. A path is palindromic if the characters along the path can...
Input: List
Output: Computed result
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OA [CodeSignal] Final Prices After Discount


Category: Array coding problem
You are given an array prices where prices[i] is the price of an item. For each item at index i, find the first item at index j > i such that...
Input: Array
Output: Computed result
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OA [CodeSignal] Jump Game


Category: Array coding problem
You are at position i in an array. From each position, you can jump to: - i + 1 (one step forward) - Any position i + k where k ends in digit...
Input: Array
Output: Computed result
coding Medium Verified

OA [CodeSignal] Longest Subsequence With Limited Sum


Category: Array coding problem
You are given two arrays: nums (containing positive integers) and queries (each containing a target sum). For each query, return the maximum...
Input: Array
Output:** Computed result
coding Hard Verified

OA [CodeSignal] Max Throughput With Budget


Category: Algorithm coding problem
You have a pipeline of services. Each service has: - Current throughput throughput[i] - Cost to scale up by 1 unit scalecost[i] You have a fixed...
Input: List
Output: Integer
coding Hard Verified

OA [CodeSignal] Minimum Edge Reversal Root


Category: Graph coding problem
Given a directed graph (represented as a tree with directed edges), choose a root node such that the minimum number of edges must be reversed so that...
Input: Graph (nodes and edges)
Output: Integer
coding Medium Verified

OA [CodeSignal] Minimum Operation To Reduce n To 0


Category: Algorithm coding problem
Given a positive integer n, in one operation you may replace n with either: - n = n + 2^i, or - n = n - 2^i for any integer i >= 0. Find...
Input: Integer(s)
Output: Integer
coding Hard Verified

OA [CodeSignal] Purchase Optimization


Category: Array coding problem
Alex is shopping at Ozone Gallerie Mall where cubicles are arranged in non-decreasing order of prices from left to right. Given: - prices: array of...
Input: Array
Output: Integer
coding Medium Verified

OA [CodeSignal] Shortest Good Subarray


Category: Array coding problem
Given an array arr and an integer k, a subarray is called good if it contains at least k distinct integers. Return the length of the...
Input: Array
Output: Integer
coding Hard Verified

OA [CodeSignal] Touring the Building


Category: Algorithm coding problem
You are on floor 0 of a building and need to reach floor n. You can use either the lift or stairs. Lift: - Takes t1 time per floor -...
Input: Given input
Output: Computed result
coding Medium Verified

[CodeSignal] Maximum Zero-Sum Triplets


Category: Array coding problem
# Question You are given an array A of integers. A triplet is a sequence of three consecutive elements. A triplet is called zero-sum if the...
Input: Array
Output: Computed result
coding Easy Verified

[CodeSignal] Coin Table Game


Category: String coding problem
# Question A player is playing a game in which coins are placed on and removed from a table. The game consists of multiple rounds. At the beginning...
Input: String
Output: Computed result
coding Easy Verified

[CodeSignal] Count Non-Dominant Elements


Category: Array coding problem
# Question Given an array of integers numbers, count all elements that are not equal to numbers[0] or numbers[1] (if those indices exist in the...
Input: Array of integers
Output: Computed result
coding Easy Verified

[CodeSignal] Sort Words By Vowel Consonant Difference


Category: Array coding problem
# Question You are given a string text consisting of unique lowercase English words separated by spaces. For each word, compute the absolute...
Input: Array
Output:** Computed result
coding Medium Verified

[CodeSignal] Warehouse Robot Commands


Category: Matrix coding problem
# Question In a highly automated warehouse, a robot organizes packages stored in a rectangular grid. The grid is represented as a 2D list of integers...
Input: Matrix (2D array)
Output: Computed result
coding Hard Verified

[CodeSignal] House Segments After Destruction


Category: Array coding problem
# Question You are monitoring the building density in a district of houses. The district is represented as a number line, where each house is located...
Input: Array of integers
Output: Array
coding Hard Verified

[CodeSignal] Warehouse Emergency Deliveries


Category: Array coding problem
Amazon has opened a new warehouse recently. There are no products in the warehouse currently. The warehouse is under inspection for n days. The...
Input: Array
Output: Integer
coding Hard Verified

[CodeSignal] Permutation Sorter


Category: Combinatorics coding problem
Amazon engineers are testing a new tool, the Permutation Sorter, built to reorder sequences using limited operations. Given a permutation of...
Input: Integer(s)
Output: Integer
coding Hard Verified

[CodeSignal] Maximum Product Rating


Category: Array coding problem
The engineers at Amazon are working on a new rating system for their products. For each product, an array customer_rating is maintained for the...
Input: Array
Output: Computed result
coding Medium Verified

[CodeSignal] Drone Hub Travel


Category: Array coding problem
Amazon is expanding its next-generation drone delivery network, consisting of m hubs arranged in a circular ring (Hub 1 is adjacent to Hub m)....
Input: Array
Output: Computed result
coding Medium Verified

[CodeSignal] Minimum Security Groups


Category: Array coding problem
A financial services company has requested AWS for a private deployment of its cloud network. There are n servers in the network where the security...
Input: Array
Output: Integer
coding Medium Verified

[CodeSignal] Maximum Secure Deliveries


Category: Array coding problem
You are given an array deliveryLogs of size n, where each element represents the number of parts delivered in the i-th log. You are also given...
Input: Array
Output: Integer
coding Medium Verified

Service Log Aggregator


Category: Trie-based coding problem
A distributed system emits log entries from multiple services and worker threads. Each log entry is a colon-separated string in the format...
Input: Array
Output: Computed result

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