Citadel Interview Questions

Implement a hashtable data structure that handles hash collisions using probing.

In Python, use object-oriented design to implement a defaultdict from scratch.

Given a matrix and the coordinates of the top-left and bottom-right corners, calculate the sum of the elements within the specified submatrix in (1) linear time and (2) constant time. You are allowed to preprocess the matrix.

Write the code for a multi-reader/single-writer lock.

Write a program to schedule a stream of pizza delivery orders.

Implement the native map function for arrays.

In C++, would you prefer to store pointers or references in a vector? Explain your reasoning.

In C++ templates, in what cases is the keyword 'typename' used?

How do you implement a hash map in C#?

Implement the k-nearest neighbor algorithm.

Given a vector of edges (e.g., A-B, A-C, C-D), write a function to determine if the resulting graph is a tree. If it is a tree, return its root.

1. Given a triangle defined by its vertices, determine whether a given point is inside the triangle. 2. Given a list of times, find the number of pairs of times that add up to 60.