Citadel Software Engineer Onsite Coding Questions

### Problem Overview - Find all distinct goodness values for this problem, where goodness is the bitwise-OR of any strictly increasing subsequence, and return them sorted. - Input: int arr[n]; Output:

First Coding Interview I was given a to reverse a given string. It was easy. void reverse(char begin, char end) { \t\t\t// to do function } void reverseString(std::string str) { \treverse(str.data(), str.data() + str.size()); } int main() { std::string str = "Reverse"...

LeetCode #295: Find Median from Data Stream. Difficulty: Hard. Topics: Two Pointers, Design, Sorting, Heap (Priority Queue), Data Stream. Asked at Citadel in the last 6 months.

LeetCode #1801: Number of Orders in the Backlog. Difficulty: Medium. Topics: Array, Heap (Priority Queue), Simulation. Asked at Citadel in the last 6 months.

LeetCode #127: Word Ladder. Difficulty: Hard. Topics: Hash Table, String, Breadth-First Search. Asked at Citadel in the last 6 months.

LeetCode #348: Design Tic-Tac-Toe. Difficulty: Medium. Topics: Array, Hash Table, Design, Matrix, Simulation. Asked at Citadel in the last 6 months.

LeetCode #150: Evaluate Reverse Polish Notation. Difficulty: Medium. Topics: Array, Math, Stack. Asked at Citadel in the last 6 months.

LeetCode #1004: Max Consecutive Ones III. Difficulty: Medium. Topics: Array, Binary Search, Sliding Window, Prefix Sum. Asked at Citadel in the last 6 months.

LeetCode #155: Min Stack. Difficulty: Medium. Topics: Stack, Design. Asked at Citadel in the last 6 months.

LeetCode #1244: Design A Leaderboard. Difficulty: Medium. Topics: Hash Table, Design, Sorting. Asked at Citadel in the last 6 months.

LeetCode #3484: Design Spreadsheet. Difficulty: Medium. Topics: Array, Hash Table, String, Design, Matrix. Asked at Citadel in the last 6 months.

LeetCode #332: Reconstruct Itinerary. Difficulty: Hard. Topics: Array, String, Depth-First Search, Graph Theory, Sorting, Heap (Priority Queue), Eulerian Circuit. Asked at Citadel in the last 6 months.

LeetCode #2050: Parallel Courses III. Difficulty: Hard. Topics: Array, Dynamic Programming, Graph Theory, Topological Sort. Asked at Citadel in the last 6 months.

## Problem: Minimum Path to Target in a Binary Tree (Variant of LC 112) Given the root of a binary tree `root` and an integer `targetSum`. A **root-to-leaf** path is a sequence of nodes starting at t

## Problem: Refactor and Optimize a Slow Function Given an integer array `output` (length `n`, `n >= 1`), you need to refactor and speed up a “correct but slow” implementation. The final return valu

You are given a stream of order records. Each record has: - `exchange_id`: exchange identifier (string) - `price`: price (integer) - `quantity`: quantity (positive integer) - `order_type`: side (`"bi

Implement a system that supports task insertion, deletion, and execution. The implementation should use a priority queue with lazy deletion. ### Sample Input ``` "add task1 with priority 1, add task3

Implement a data structure that supports weighted insertion and deletion, and allows for random sampling by weight. ### Sample Input ``` "insert 5, insert 10, delete 5, sample" ``` ### Sample Output

Write a simulation of the 2048 game. Encode and decode the game state to and from a compressed long long integer. ### Sample Input ``` "[[0,2,4,8],[16,32,64,128],[256,512,1024,2048],[4096,8192,16384,

Implement a Binary Search Tree (BST) class from scratch in C++ with the following functions: insert, search, delete. ### Sample Input ``` Insert: [5, 3, 6, 2, 4, 7], Search 4, Delete 3, Search 3 ```