Facebook Hacker Cup is an annual algorithmic programming contest that attracts students, professionals, and experts worldwide. Top performers may receive interview calls from Facebook for Software Developer roles.
What is the process?
Facebook Hacker Cup is particularly known for its different environments used for Judging and the variety of problems. It is conducted in many rounds where the difficulty of algorithmic challenges keeps on increasing.
What are the prizes? (May vary year to year)
The 25 finalists will receive the following prizes (in USD:
- 1st Place: $20,000 USD
- 2nd Place: $10,000 USD
- 3rd Place: $5,000 USD
- 4th Place: $3,000 USD
- 5th Place: $1,000 USD
- 6th-10th Place: $500 USD
- 11th-15th Place: $300 USD
- 16th-25th Place: $200 USD
Organized in the month of August Facebook Hacker cup is conducted in 4 series round:
- Qualification round: This is the easiest round in which at least 1 problem needs to be solved successfully in order to advance to the next round. This round lasts for 72 hours.
- Round 1: Selected candidates enter Round 1, a 24-hour contest where they must earn a set minimum score (decided each year) to qualify for Round 2. This round is harder than the qualification stage.
- Round 2: Candidates selected from round 1 advance to participate in round 2 and compete in a 3-hour format contest. The top 200 participants advance to Round 3 and the top 500 participants are awarded Hackercup T-shirts.
- Round 3: Top 200 participants compete in this 3-hour format contest and the top 25 qualify for Onsite Final. From now on the problem set gets tough.
- Onsite Final: The top 25 participants compete at Facebook’s headquarters for the Hacker Cup title and trophy. The problems are highly challenging, and the final round lasts 4 hours. The winner is crowned the Hacker Cup champion.
And the 1st person on the leaderboard bags the title and basks in glory.
Format and Environment
The judging format of the Facebook hacker cup is quite different from other annual programming contests like ACM-ICPC or IOI.
- When the contest begins users are required to login into the website.
- After logging in they are presented with the problem set. After you think you have solved a problem and are sure about its correctness, you have to download an input test file.
- As soon as the input test file is downloaded a timer of 6 minutes commences and in that window of time you are required to run the input test file over your code and form a test file. Within 6 minutes you need to submit both the code and the output text file.
- You can submit more than once and only the last correct submission will be used for evaluation.
- Once the timer expires you will be unable to submit the solution for that problem again. A time penalty is the sum of the submission times of a problem.
How to prepare?
Facebook Hacker cup is particularly famous for its innovative and mind-tickling algorithmic challenges. Inclined more towards mathematics and a combination of various concepts hacker cups test knowledge, implementation, accuracy, speed, conceptuality, and almost everything by its different rounds. You need to be fast in order to survive further rounds and innovative to survive the initial long-timed rounds. These are the main topics that should be done thoroughly as problems are generally asked from more than 1 topic combined.
Number Theory
- Euclidian and extended Euclidian algorithm
- Modular Arithmetic and modular inverse
- Prime generation (Sieve and Segmented Sieve)
- Fermat`s theorem
- Euler Totient function
- Miller Rabin primality test
- Chinese remainder Theorem
- Lucas theorem.
Greedy Algorithms
Binary search
- TopCoder-Binary Search
- Binary Search
- Ubiquitous Binary Search - Get a grasp of discrete and continuous binary search.
Data Structures
- Linked lists
- Binary search tree
- Binary Indexed Tree or Fenwick tree
- Segment Tree (RMQ, Range Sum, and Lazy Propagation)
- Red-Black trees
- Hashing
An extensive list of Data structures
Graph Algorithms
- Breadth-First Search (BFS)
- Depth First Search (DFS)
- Shortest Path from source to all vertices **Dijkstra**
- Shortest Path from every vertex to every other vertex **Floyd Warshall**
- Minimum Spanning tree **Prim**
- Minimum Spanning tree **Kruskal**
- Topological Sort
- Johnson’s algorithm
- Articulation Points (or Cut Vertices) in a Graph
- Bridges in a graph
All Graph Algorithms
String Algorithms
Learning library functions for String actually proves very helpful (C++: See this and this, String in Java).
Dynamic programming
Dynamic programming is quite important and can be infused and asked with various other topics. Some different types of DP concepts are: Classic DP
- Longest Common Subsequence
- Longest Increasing Subsequence
- Edit Distance
- Minimum Partition
- Ways to Cover a Distance
- Longest Path In Matrix
- Subset Sum Problem
- Optimal Strategy for a Game
- 0-1 Knapsack Problem
- Assembly Line Scheduling
Computational geometry
All in all Facebook Hacker cup is a very challenging contest and a person needs a gigantic amount of training and perseverance and all the standard topics need to be etched and understood. Practice is the only way to do so! Extra Points:
- Practice on Codeforces (especially the GYM section) and TopCoder Arena. This will truly help in basic understanding.
- Facebook Hacker Cup's problems have a different style than Codeforces and Topcoder, probably the best comparison would be with Google Code Jam which has a similar format.
- Go through previous Facebook - HackerCup questions and get familiar with the format of the contest.