Citadel interview notes, page 5 of 14

“Classic topological sort.” The rest of the author's notes on Software Engineer interview at Citadel, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“The key move is recognizing that |X − Y| follows a triangular distribution on [0, 100] with PDF f(d) = 2(100 − d) / 10000.” The rest of the author's notes on Software Engineer interview at Citadel, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“More open-ended than I expected for an OA.” The rest of the author's notes on Software Engineer interview at Citadel, Online Assessment (OA) round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“The conditional probability part was manageable once I set up the sample space carefully.” The rest of the author's notes on Data Scientist interview at Citadel, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“This is where things got uncomfortable fast.” The rest of the author's notes on Software Engineer interview at Citadel, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“I started with a hash set of (x, y) coordinates for live cells, which felt right.” The rest of the author's notes on Software Engineer interview at Citadel, Onsite - Coding / Algorithms round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“My first instinct was a sorted array with prefix sums, which gets you sample() in O(log n) via binary search but blows up on insert and delete.” The rest of the author's notes on Software Engineer interview at Citadel, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“This one took me a while to get traction on.” The rest of the author's notes on Software Engineer interview at Citadel, Onsite - System Design / Architecture round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“I fumbled this a little because I wasn't expecting them to go so direct so early.” The rest of the author's notes on Software Engineer interview at Citadel, Recruiter / HR Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“My first instinct was greedy, pick the days where the sum of active image costs is highest and apply the discount there.” The rest of the author's notes on Software Engineer interview at Citadel, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.