This is the list of problems from all past IPSC contests.
Please note that all IPSC problems are licensed under the CC BY-SA 3.0 license.
| IPSC 2018 | Input data packages, Problems and solutions booklet |
|---|---|
| Armed bandit |
Find any output + the lex. min. output of a slot machine.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Brain fold |
Fold paper many times, cut it once, count pieces.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Counting rectangles |
Count sets of n rectangles that differ after coordinate compression.
|
| Delightful |
Write programs in ternary assembler.
|
| Encrypted romance |
Count sparse collisions for a collection of hash functions.
Input files:
Easy input data set – E1,
Hard input data set – E2.
|
| Farmer's code |
Decipher the way apple tree crossing works.
Input files:
Dashboard.
|
| Git gud |
List all files in a git repository.
|
| Hats of various colors |
Write programs that play a hat puzzle in parallel.
Input files:
Helper program for testing.
|
| Incorrect expression |
Find all possible values after one character is changed in an expression.
Input files:
Easy input data set – I1,
Hard input data set – I2.
|
| Jumping over walls |
Construct the smallest maze in which you need to use all directions of jumps.
|
| Kids draw the darndest things |
Compute exact values of a weird continuous function.
Input files:
Easy input data set – K1,
Hard input data set – K2.
|
| Lethargic foe |
Quickly win games of symmetric chess.
|
| McDroid's |
Run a restaurant for robots.
Input files:
Dashboard.
|
| IPSC 2018 practice session | |
| Partitioning a square |
Find the smallest square that can be divided into n equal regions.
Input files:
Easy input data set – P1,
Hard input data set – P2.
|
| Qizz Quzz |
Check validity of generalized Fizz Buzz sequences.
Input files:
Easy input data set – Q1,
Hard input data set – Q2.
|
| Raw data |
Make a POST request to our webserver.
|
| IPSC 2017 | Input data packages, Problems and solutions booklet |
| Automated flooding |
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Bishopian paths |
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Collector's dilemma |
Input files:
Easy input data set – C1,
Hard input data set – C2.
|
| Dazzling digits |
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| Elevation alteration |
Input files:
Easy input data set – E1,
Hard input data set – E2 (generator).
|
| Flipping and cutting |
Input files:
Easy input data set – F1,
Hard input data set – F2.
|
| Gunfight | |
| Holy cow, Vim! | |
| Internet problem |
Input files:
Easy input data set – I1,
Hard input data set – I2.
|
| Judicious cuts |
Input files:
Easy input data set – J1,
Hard input data set – J2.
|
| Kirk or Picard? |
Input files:
Input data set – K.
|
| Lucky draws | |
| Matching pairs |
Input files:
Input data set – M.
|
| IPSC 2017 practice session | |
| Queue skipping |
Input files:
Easy input data set – Q1,
Hard input data set – Q2 (generator).
|
| Russian roulette |
Input files:
Easy input data set – R1,
Hard input data set – R2.
|
| St. Ives |
Input files:
Easy input data set – S1,
Hard input data set – S2.
|
| IPSC 2016 | Input data packages, Problems and solutions booklet |
| Avoiding accidents |
Overlap and concatenate a few strings.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Bounding box |
Place a given set of balls into a 3D box.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Counting swaps |
Count the ways of sorting a sequence using fewest swaps.
Input files:
Easy input data set – C1,
Hard input data set – C2.
|
| Dumb clicking |
Win a simple browser-based clicking game.
Input files:
Easy game – D1,
Hard game – D2.
|
| Evil minesweeper |
Write an evil backend for a minesweeper game.
Input files:
Easy input data set – E1,
Hard input data set – E2.
Solutions:
Solution,
Booklet,
One possible correct output for E1,
One possible correct output for E2,
C++ program that precomputes solutions of small instances,
C++ header file with precomputed solutions of small instances,
C++ program solving both subproblems,
Python 3 program to check submissions.
|
| Ferries |
Get an object from position x to position y using given permutations.
Input files:
Easy input data set – F1,
Hard input data set – F2.
|
| Greatest number |
Remove symbols from a simple expression to maximize its value.
Input files:
Easy input data set – G1,
Hard input data set – G2.
|
| Heavy snowfall |
Simulate snowfall and snow plowing on a tree.
|
| Intelligence report |
Recover passwords from images.
Input files:
Easy input data set – I1,
Hard input data set – I2.
|
| Jumping queues |
Choose the best checkout line in a fairly complicated setting.
|
| Kill switch |
Given a 'sorting' algorithm, find the shortest input it does not sort.
|
| Luxor Catch-ya! |
Solve a captcha that uses hieroglyphics.
Input files:
A zip file with test data for both L1 and L2.
|
| Mana troubles |
Tap Magic the Gathering lands for mana.
|
| IPSC 2016 practice session | |
| Subsequence |
Check whether one string is a subsequence of another.
Input files:
Easy input data set – S1,
Hard input data set – S2 (generator).
|
| Turning gears |
Given a machine with many linked gears, how will they rotate?
Input files:
Easy input data set – T1,
Hard input data set – T2.
|
| Ultimate magic rectangles |
Compute the number of generalized magic squares.
Input files:
Easy input data set – U1,
Hard input data set – U2.
|
| IPSC 2015 | Input data packages, Problems and solutions booklet |
| A+B |
Build the largest sum A+B from given digits.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Bawdy Boil-brained Bugbear |
Build a three-word insult with the given strength.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Chess Pieces |
Play a game of chess and create many identical pieces.
|
| Dijkstra's Nightmare |
Show that Dijkstra's algorithm can be exponential when negative edges are allowed.
|
| Enclosure |
Catch the cat!
|
| Familiar Couples |
Disjoint set union "in two dimensions".
Input files:
Easy input data set – F1,
Hard input data set – F2 (generator).
|
| Generating Synergy |
Coloring a rooted tree up to a given depth.
Input files:
Easy input data set – G1,
Hard input data set – G2 (generator).
|
| Humble Captains |
Dividing kids into teams and optimizing stuff about pairs of friends.
Input files:
Easy input data set – H1,
Hard input data set – H2.
|
| Inexpensive Travel |
Find all shortest paths for cyclists with various distance/ascent preferences.
Input files:
Easy input data set – I1,
Hard input data set – I2 (generator).
|
| Juicy Dot Coms |
Crack an old 16-bit .COM file.
Input files:
File for subproblem J1,
File for subproblem J2.
|
| Klingelt das Glockenspiel |
Listen to bells on a wall and determine their locations.
Input files:
File for subproblem K1,
File for subproblem K2.
|
| Lunchtime! |
Make sense of a foreign-language menu by ordering food in a smart way.
Input files:
Easy input data set – L1,
Hard input data set – L2.
|
| Make*me-an+[integer!] |
Write programs in a restricted subset of JavaScript.
|
| IPSC 2015 practice session | |
| Solitaire |
Compute the number of rounds of a simple game of solitaire.
Input files:
Easy input data set – S1,
Hard input data set – S2 (generator).
|
| Town |
Given a box of digits, number as many houses as you can.
Input files:
Easy input data set – T1,
Hard input data set – T2.
|
| Unusual Game Show |
Monty Hall problem with a twist.
Input files:
Easy input data set – U1,
Hard input data set – U2.
|
| IPSC 2014 | Input data packages, Problems and solutions booklet |
| Adjusting passwords |
Check whether using backspace pays off.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Beating the game |
Play a one-dimensional version of the game 2048.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Copier |
Reverse an operation that copies a part of a string.
Input files:
Easy input data set – C1,
Hard input data set – C2.
|
| Disk space eater |
Unzip one exabyte of zeros.
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| Empathy system |
Recognize four different emotions in photos.
Input files:
Input data set – E.
|
| Find a sudoku in π |
Find nine matching rows of a sudoku in π.
|
| Game on a conveyor belt |
Play a surprisingly complicated game of NIM on a conveyor belt.
Input files:
Easy input data set – G1,
Hard input data set – G2.
|
| Hashsets |
Find hard inputs for standard hashsets in C++ and Java.
Input files:
C++ program – h.cc,
Java program – h.java.
|
| Intrepid cave explorer |
Label all vertices of a tree optimally.
Input files:
Easy input data set – I1,
Hard input data set – I2.
|
| Judging programs |
Discover which programs do solve a given problem and which ones don't.
Input files:
Easy input data set – J1,
Easy input data set – J2.
|
| Knowledge test |
Solve a crossword.
Input files:
Easy input data set – K1,
Hard input data set – K2.
|
| Let there be sound |
Decode a sound file... and more.
Input files:
Easy input data set – L1,
Easy input data set – L2.
|
| Maximum enjoyment |
Solve a maximum flow problem with a path length limit.
Input files:
Easy input data set – M1,
Hard input data set – M2.
|
| IPSC 2014 practice session | |
| Say it loudly! |
Find the *LOUDEST* sentence.
Input files:
Easy input data set – S1,
Hard input data set – S2.
|
| Two covers |
Which parts of a sequence are covered twice?
Input files:
Easy input data set – T1,
Hard input data set – T2.
|
| Urban planning |
Find the smallest road network with the same transitive closure.
Input files:
Easy input data set – U1,
Hard input data set – U2.
|
| IPSC 2013 | Input data packages, Problems and solutions booklet |
| Advice for Olivia |
Pay a sum using sufficiently few coins and banknotes.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Boredom buster |
Find the best way of breaking a number into ones.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Code Inception |
Analyze programs that output instructions how to modify them.
|
| Do the grading |
Write a grader for the practice task R.
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| Exploring the cave |
Find a NFA with n states such that the corresponding DFA has d states.
Input files:
Easy input data set – E1,
Hard input data set – E2.
|
| Feeling lucky? |
Play a weighing game that involves randomness.
Solutions:
Booklet.
|
| Grid travel |
Find the longest path from A to B on a rectangular grid.
Input files:
Easy input data set – G1,
Hard input data set – G2.
|
| Histiaeus |
Locate a hidden message carried by a slave.
|
| Invisible cats |
Descramble a collection of images and find all cats.
|
| Just a single gate |
Find all universal ternary gates.
|
| Knee problems |
Count the ways of walking up and down the stairs.
Input files:
Easy input data set – K1,
Hard input data set – K2.
|
| Labyrinth |
Find your way through a seemingly simple labyrinth with buttons.
Input files:
JavaScript game – L1, L2.
|
| Morning hassle |
Find the fastest way to drive your car over railroad crossings.
Input files:
Easy input data set – M1,
Hard input data set – M2.
|
| IPSC 2013 practice session | |
| Plus one |
Increment the given number by 1... with a twist!
Input files:
Easy input data set – P1,
Hard input data set – P2.
|
| Quite the cheater! |
Find a sequence with a given mean and a given variance.
Input files:
Easy input data set – Q1,
Hard input data set – Q2.
|
| Rearranged alphabet |
Find a short string that contains each permutation as a subsequence.
|
| IPSC 2012 | Input data packages, Problems and solutions booklet |
| Abundance of sweets |
Look for all candies in a matrix of characters.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| (blank) |
Solve a task with no problem statement, using just the messages from the grader.
Solutions:
Booklet,
Python program for the last step of solving B1.
|
| Card game |
Find the best strategy in a card game involving probability.
Input files:
Easy input data set – C1,
Hard input data set – C2.
|
| Data mania |
Answer queries about data from past years of IPSC.
|
| Evil matching |
Solve a pattern matching problem in which we can add adjacent elements of text.
|
| Fair coin toss |
Try to simulate a fair coin by xor-ing biased ones.
Input files:
Easy input data set – F1,
Hard input data set – F2.
|
| Gems in the maze |
Find the longest path in a graph with outdegree 1.
Input files:
Easy input data set – G1,
Hard input data set – G2.
|
| Harvesting potatoes |
Plan the optimal schedule for a harvester.
Input files:
Easy input data set – H1,
Hard input data set – H2.
|
| Invert the you-know-what |
Recover a password from a related MD5 hash.
Input files:
Password file for both data sets – I1, I2.
Solutions:
Booklet,
Decrypted passwords.
|
| Jukebox |
Convert a recording of a simple song into musical notes.
|
| Keys and locks |
Determine the master key for a pin tumbler lock.
|
| Light in a room |
Compute the area lit by a cone of light in a room.
Input files:
Easy input data set – L1,
Hard input data set – L2.
|
| Matrix nightmare |
Given a polynomial, find a matrix such that its determinant is the given polynomial.
Input files:
Easy input data set – M1,
Hard input data set – M2.
|
| IPSC 2012 practice session | |
| Partitioning containers |
Split numbers with sum S into two subsets of size at most S/2 and possibly one extra element.
Input files:
Easy input data set – P1,
Hard input data set – P2.
Solutions:
Booklet.
|
| Quaint encryption |
Find one alphabet permutation consistent with a given substitution cipher.
Input files:
Easy input data set – Q1,
Hard input data set – Q2.
Solutions:
Booklet.
|
| Rebel Alliance attacks |
In a sphere, find all grid points with integer distance to the center.
Input files:
Easy input data set – R1,
Hard input data set – R2.
Solutions:
Booklet.
|
| IPSC 2011 | Input data packages, Problems and solutions booklet |
| Against a rock play Spock |
Always win in a Rock-Paper-Scissors-Lizard-Spock game.
Input files:
Easy input data set – A1,
Hard input data set – A2.
Solutions:
Booklet,
Program solving both data sets.
|
| BFS killer |
Find a maze for which BFS needs a long queue.
Input files:
Easy input data set – B1.
|
| Candy for each guess |
Find the optimal strategies for 'binary search' played as a game.
Input files:
Easy input data set – C1,
Hard input data set – C2.
|
| Divide the rectangle |
Divide a rectangle into two equal parts, each containing one given cell.
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| Elementary math |
Compute square roots of numbers and format the output nicely.
Input files:
Easy input data set – E1,
Hard input data set – E2.
|
| Flipping coins |
Find the optimal strategy in a puzzle about guessing your coin without seeing it.
|
| Grid surveillance |
Find a persistent data structure that supports additions and rectangle queries.
Input files:
Easy input data set – G1,
Hard input data set – G2.
|
| HQ0-9+-INCOMPUTABLE?! |
Write a program that outputs your TIS in a very unfriendly language.
|
| Inverting bits |
Compute the negations of many bits using few NOTs.
|
| Jedi academy |
Compute lots of ray-object intersections.
Input files:
Easy input data set – J1,
Hard input data set – J2.
|
| Keep clicking, keep flipping |
Play a game on a graph in which you flip vertex colors and adjacent edges.
Input files:
Easy input data set – K1,
Hard input data set – K2.
|
| Lame crypto |
Break a cryptographic protocol in 'real time'.
Input files:
Easy input data set – L1,
Hard input data set – L2.
Solutions:
Booklet.
|
| My little puppy |
Take care of a virtual puppy for some bonus time.
Solutions:
Booklet.
|
| IPSC 2011 practice session | |
| Pancakes! |
Maximize the number of pancakes given the resources you have.
Input files:
Easy input data set – P1,
Hard input data set – P2.
|
| Quality of Service |
Assemble the problem statement from many sparse parts.
Input files:
Easy input data set – Q1,
Hard input data set – Q2.
Solutions:
Booklet,
output checker.
|
| Rotate to divide |
Find a number that gets divided by K when we rotate it.
Input files:
Easy input data set – R1,
Hard input data set – R2.
|
| IPSC 2010 | Input data packages, Problems and solutions booklet |
| Antisort |
Do NOT sort the input sequence.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Broadway |
Find the shortest path in Manhattan that includes the Broadway.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Cells |
Evaluate spreadsheet cells.
Input files:
Easy input data set – C1,
Hard input data set – C2.
|
| Dragon Slayer |
Kill a magic dragon using two magic swords.
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| Eyjafjallajökull |
Find the vulcano by making online measurements of the ash cloud.
Input files:
Easy input data set – E1,
Hard input data set – E2.
Solutions:
Booklet,
C code implementing a good player.
|
| Flawed Code |
Find inputs for which incorrect greedy algorithms fail.
|
| Grid is good |
Draw a binary tree into a small grid.
Input files:
Easy input data set – G1,
Hard input data set – G2.
|
| Hash |
Invert two hashes that use MD5 incorrectly.
|
| Inside job |
For a dart thrown onto a polygon, compute the expected sum of distances from the dart to all its sides.
Input files:
Easy input data set – I1,
Hard input data set – I2.
|
| Jimmy the Acting Teacher |
Create a schedule of meetings where each pair meets once.
Input files:
Easy input data set – J1,
Hard input data set – J2.
|
| Klingon High Council Training |
Find the optimal strategy for a game played with ships in a 3D grid.
Input files:
Easy input data set – K1,
Hard input data set – K2.
|
| Lovely stamps |
Compute the number of ways in which some stamps can be bought.
Input files:
Easy input data set – L1,
Hard input data set – L2.
|
| Mass psychoanalysis |
Guess two thirds of the average of all guesses.
Solutions:
Booklet.
|
| IPSC 2010 practice session | |
| Piece of cake! |
Cut a cake shaped like a box in a way that leaves the largest uncut part.
Input files:
Easy input data set – P1,
Hard input data set – P2.
|
| Quick growth |
Memory is being filled by multiplying arrays, compute the sum of all elements.
Input files:
Easy input data set – Q1,
Hard input data set – Q2.
|
| Round and round it goes |
Find constants that turn the given program into the best infinite loop.
|
| IPSC 2009 | Input data packages, Problems and solutions booklet |
| Arithmetics for dummies |
Find the result of an expression computed on an oldschool calculator.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Bouncing balls |
Find the state of a box full of bouncing balls.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Cryptic punchcards |
Read text stored on punchcards.
|
| Don't worry about wrong answers |
A weird problem in which almost any submission is accepted.
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| Easy representation |
Compute area of a pictorial representation of a correctly parentesized string.
Input files:
Easy input data set – E1,
Hard input data set – E2.
|
| Fish Fillets |
Solve two new levels of the Fish Fillets puzzle.
Input files:
Easy input data set – F1,
Hard input data set – F2.
|
| Going to the movies |
Compute the probability that all girls will find a place to sit at the cinema.
Input files:
Easy input data set – G1,
Hard input data set – G2.
|
| Hunt! |
Direct wolves to hunt sheep in real time.
|
| Instructions |
Implement '+8' and 'next with same popcount' using a very restricted assembler.
|
| Jumbo Airlines |
Compute the number of ways of seating people in an airplane.
Input files:
Easy input data set – J1,
Hard input data set – J2.
|
| Karl's shopping |
Find the smallest amount of additional cash needed when paying by various vouchers.
Input files:
Easy input data set – K1,
Hard input data set – K2.
|
| Let there be rainbows! |
A tree is being colored using 7 colors, construct its final state.
Input files:
Easy input data set – L1,
Hard input data set – L2.
|
| Muzidabutur |
Match regular expressions that are written in verbose English.
Input files:
Easy input data set – M1,
Hard input data set – M2.
|
| IPSC 2009 practice session | |
| Pathfinding |
Given a maze, find a reasonably short solution.
Input files:
Easy input data set – P1,
Hard input data set – P2.
|
| Quick search |
Given a rectangle divided into polygons, find two identical ones.
Input files:
Easy input,
Hard input.
|
| Reverse quick search |
Create valid test data for problem 'Quick search'.
Input files:
Easy input data set – R1,
Hard input data set – R2.
|
| IPSC 2008 | Input data packages |
| Army Strength |
Find the winner in a battle of two armies where the weakest unit always gets killed.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Breaking in |
Find the server that gives you the most access when compromised.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Comparison Mysteries |
Show that x==-x has a nontrivial solution in ints, and that equality is not transitive.
Solutions:
Solution.
|
| Discover All Sets |
Play a generalized version of the game Sets.
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| Expected Cost |
Compute the expected cost of a minimum spanning tree for a graph with random edge weights.
Input files:
Easy input data set – E1,
Hard input data set – E2.
|
| Find the Meaning |
A message is somehow hidden in the input file, find it.
Input files:
Easy input data set – F1,
Hard input data set – F2.
|
| Game on Words |
In real time, play against us a game where the players extend a string until it becomes a word.
Input files:
Easy input data set – G1,
Hard input data set – G2.
Solutions:
Solution,
C++ program that plays the game optimally.
|
| Hidden Text |
Show that blurred text can be recovered if you know the font.
Input files:
Easy input data set - H1,
Difficult input data set - H2.
|
| Inventing Test Data |
Given a weighted tree T, find the lightest complete graph for which T is the only MST.
Input files:
Easy input data set – I1,
Hard input data set – I2.
|
| Just a Single Lie |
Find the optimal strategy in a number guessing game where you may receive a single lie.
Input files:
Easy input data set – J1,
Hard input data set – J2.
|
| K Equal Digits |
Find the largest number with all digits equal that matches a set of criteria.
Input files:
Easy input data set – K1,
Hard input data set – K2.
|
| Large party |
Count the ways in which men and women can sit at a table if large clusters of women are forbidden.
Input files:
Easy input data set – L1,
Hard input data set – L2.
|
| IPSC 2008 practice session | |
| Perfect Rhyme |
Given a word, find another word that is the best rhyme.
Input files:
Easy input data set – P1,
Hard input data set – P2.
|
| Quiz |
Answer all trivia questions about the history of IPSC correctly.
Input files:
Easy input data set – Q1,
Hard input data set – Q2.
|
| Railroad Map |
Given a graph, replace all non-branching paths by direct edges.
Input files:
Easy input data set – R1,
Hard input data set – R2.
|
| IPSC 2007 | Input data packages |
| Anti-Blot System |
Fix a simple equation that has a ink blot covering part of a number.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Bus Story |
Check whether a story about passengers boarding and leaving a bus may be true.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Calling Me Calling You |
Purchase enough free numbers to allow a group of friends call each other for free.
Input files:
Easy input data set – C1,
Hard input data set – C2.
Solutions:
Solution,
C program that solves both data sets.
|
| Delicious Cake |
Count the ways of cutting a rectangular cake into pieces.
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| Enhancing IPSC Rules |
Given a rock-paper-scissors game as a set of pictures, compute who won.
|
| Finally some Sudoku |
Solve several Sudoku instances that share some of their values.
Input files:
Easy input,
Hard input.
|
| Guess the Numbers |
In real time, guess a sequence by choosing another and getting their scalar product.
Input files:
Easy input data set – G1,
Hard input data set – G2.
Solutions:
Solution.
|
| Here-There |
Find the shortest path on a fractal board.
Input files:
Easy input data set – H1,
Hard input data set – H2.
|
| Internet is Faulty |
Minimize the expected transfer time via a network with faulty links.
Input files:
Easy input data set – I1,
Hard input data set – I2.
|
| jPix |
Draw lines and compute area reached by a flood fill on a huge grid.
Input files:
Easy input data set – J1,
Hard input data set – J2.
|
| Know Your Crypto |
Solve a simple cipher and reverse a seemingly random one.
Input files:
Easy input data set – K1,
Hard input data set – K2.
|
| Little Peter's Tower |
Maximize the expected height of a tower built from randomly drawn blocks.
Input files:
Easy input data set – L1,
Hard input data set – L2.
|
| IPSC 2007 practice session | |
| Paradox With Averages |
If a person moves from group A to group B, the average IQ of both groups may increase.
Input files:
Easy input data set – P1,
Hard input data set – P2.
|
| QuackQuack |
Factorize and duplicate the queue in our special queue-based scripting language.
|
| Rasterized Lines |
Given N, in how many ways can one draw a rasterized line segment with N black pixels?
Input files:
Easy input data set – R1,
Hard input data set – R2.
|
| IPSC 2006 | Input data packages |
| Another Candies |
Kids brought candies, divide them evenly.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Biased Standings |
Given the teams' wishes, produce a ranklist that matches them as closely as possible.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Counting Subsequences |
Count all contiguous subsequences with sum equal to 47.
Input files:
Easy input data set – C1,
Hard input data set – C2.
|
| Digital Calculator |
Compute the first few and the last few digits of a factorial.
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| Encoded Messages |
Decrypt a permutation cipher and a substitution cipher.
Input files:
Easy input data set – E1,
Hard input data set – E2.
|
| Fractal Plants |
Find the center of mass of a fractal plant.
Input files:
Easy input data set – F1,
Hard input data set – F2.
|
| Gotta Pick'em All |
Count the largest subsets of {1,...,n} in which no two elements sum to a third one.
Input files:
Input data set – G.
|
| h4x0r t3h c0d3 |
Compute a discrete logarithm in a restricted setting, and create two PostScript files with the same MD5 sum.
Input files:
Easy input data set – H1,
Hard input data set – H2.
|
| Ideal Matches |
Cover a complete graph by Hamiltonian cycles that intersect in a fixed matching.
Input files:
Easy input data set – I1,
Hard input data set – I2.
Solutions:
Solution,
A C++ program to solve both data sets.
|
| Jamcode 2006 |
Given a task and a wrong program, find an input for which the program works.
Input files:
Easy input data set – J1,
Hard input data set – J2.
|
| Kruskal |
Find the optimal strategy for a NIM variant where creating a prime-sized heap wins the game.
Input files:
Easy input data set – K1,
Hard input data set – K2.
|
| Librarian |
Create a sequence of page requests that would produce more page faults if cache size is increased slightly.
|
| Matrioska |
Get the correct answer out of multiple nested file formats.
Input files:
Easy input data set – M1,
Hard input data set – M2.
Solutions:
Solution.
|
| IPSC 2006 practice session | |
| Santos Apples |
Divide a garden into two equal parts, each containing trees of a single type.
Input files:
Easy input data set – P1,
Hard input data set – P2.
|
| Labyrinth |
Simulate a robot in a simple maze.
Input files:
Easy input data set – Q1,
Hard input data set – Q2.
|
| Medical Research |
Given a sequence of numbers, answer queries about the k-th smalest one.
Input files:
Easy input data set – R1,
Hard input data set – R2.
|
| IPSC 2005 | Input data packages |
| Alpha Centauri Tennis |
Given a transcript of a tennis match, find out who won.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Bottom Coder |
Alter code so that it creates a specific output.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Crane Operator |
Given a crane and a set of boxes, compute the boxes' final positions and move them using fewest moves possible.
Input files:
Easy input data set – C1,
Hard input data set – C2.
|
| Dance Dance Revolution |
Catch as many arrows as possible in a DDR game.
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| Exact? Approximate! |
Given a decimal number, produce the simplest fraction that evaluates to that decimal after appropriate rounding.
Input files:
Easy input data set – E1,
Hard input data set – E2.
|
| Find The Right Words |
Given a set of words, assign one to each letter of the alphabet so that each word contains its letter and the total length is minimal.
Input files:
Easy input data set – F1,
Hard input data set – F2.
Solutions:
Solution,
C++ code that solves both data sets.
|
| Gears In Action |
Compute the time until a system of gears reaches a given configuration.
Input files:
Easy input data set – G1,
Hard input data set – G2.
|
| Hidden Messages |
Decrypt two pen-and-paper ciphers.
Input files:
Easy input data set – H1,
Hard input data set – H2.
Solutions:
Solution.
|
| Ignore the Garbage |
Given an upside-down digital display, find the k-th number that makes sense.
Input files:
Easy input data set – I1,
Hard input data set – I2.
|
| Just for Fun |
Solve logic puzzles for bonus time.
Input files:
Easy input data set – J1,
Hard input data set – J2.
Solutions:
Solution.
|
| IPSC 2005 practice session | |
| Polly Wanna Cracker |
Divide crackers among parrots evenly and report the exact outcome.
Input files:
Easy input data set – P1,
Hard input data set – P2.
|
| Quack Strikes Back |
Compute Fibonacci numbers and write a backwards-quine in our queue-based scripting language.
Solutions:
Solution.
|
| Rotate And Cut |
Given a string, several times cut one quarter of it off.
Input files:
Easy input data set – R1,
Hard input data set – R2.
Solutions:
Solution,
C code that solves both data sets.
|
| IPSC 2004 | Input data packages |
| Andrew's revenge |
Given a program and its output, find one matching input.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Bishops |
Place the maximum number of bishops on a generalized chessboard.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Calls |
Given a matrix of integers, check whether it is a shortest distances matrix for some graph.
Input files:
Easy input data set – C1,
Hard input data set – C2.
|
| Delayed search |
In real time, guess a number using yes/no questions, with each answer coming only after several questions.
Input files:
Easy input data set – D1,
Hard input data set – D2.
Solutions:
Solution.
|
| Electrical Circuits |
Count the number of perfect matchings in special graphs.
Input files:
Easy input data set – E1,
Hard input data set – E2.
|
| Fat Rat |
Can a sphere fit through a given pipe with obstacles?
Input files:
Easy input data set – F1,
Hard input data set – F2.
|
| Gets and Puts |
Write a sorting program and a quine in our queue-based scripting language.
|
| Hard Question – P=NP? |
Given a polygon and a set of non-intersecting rectangles, does a subset of rectangles exactly match the polygon?
Input files:
Easy input data set – H1,
Hard input data set – H2.
|
| IPSC 2004 practice session | |
| Dependency Problems |
Given package dependencies and availability, install as many as possible.
Input files:
Easy input data set – R1,
Hard input data set – R2.
|
| Censored Smiles |
Count all smiling faces in a large picture.
Input files:
Easy input data set – S1,
Hard input data set – S2.
|
| The Tiling Problem |
Tile a given floor using 2 by 1 tiles.
Input files:
Easy input data set – T1,
Hard input data set – T2.
|
| IPSC 2003 | Input data packages |
| Arranging Flowers |
Reconstruct the missing rows of a Latin square.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| begin 4 7 add |
Analyze and modify code written in PostScript.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Cinderella |
Using a digital scale, interactively identify the bag with false coins.
Solutions:
Solution.
|
| Dependency Problems |
Given package dependencies and availability, install as many as possible.
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| Enchanted Forest |
Find the smallest number of flood fills necessary to recolor a 0/1 matrix to a single color.
Input files:
Easy input data set – E1,
Hard input data set – E2.
|
| Folding the Paper |
Can a strip of paper squares be folded into the given order?
Input files:
Easy input data set – F1,
Hard input data set – F2.
|
| Got Root? |
Find the optimal strategy for a Hackenbush variant.
Input files:
Easy input data set – G1,
Hard input data set – G2.
|
| Hordes of Bacteria |
Simulate lots of iterations of a growing bacteria colony.
Input files:
Easy input data set – H1,
Hard input data set – H2.
|
| IPSC 2003 practice session | |
| Candies |
Separate three candy flavors by moving as few of them as possible.
Input files:
Easy input data set – R1,
Hard input data set – R2.
Solutions:
Correct output – R1,
Correct output – R2.
|
| Colorful Cubes |
Given cubes with colored sides, assemble a tower in which pairs of touching sides match.
Input files:
Easy input data set – S1,
Hard input data set – S2.
Solutions:
Correct output – S1,
Correct output – S2.
|
| Strange Numbers |
Convert integers between binary and our ad-hoc encoding.
Input files:
Easy input data set – T1,
Hard input data set – T2.
Solutions:
Correct output – T1,
Correct output – T2.
|
| IPSC 2002 | |
| Andews's Exams III |
Given a program, find an input for which it terminates quickly.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Load Balancing |
Find the smallest amount of rounds necessary to rebalance the load for a row of processors.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Chamber of Secrets |
By observing a digital display with a counter few segments at a time, interactively determine its value.
|
| Space Suckers |
Given a graph where each vertex has a set of properties, find a Hamiltonian path such that each property is contiguous.
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| Expressions |
Express the given number as an expression that uses as few 1s as possible.
Input files:
Easy input data set – E1,
Hard input data set – E2.
|
| (un)Fair Play |
Given a league in progress, find out whether a given team can still win it.
Input files:
Easy input data set – F1,
Hard input data set – F2.
|
| Gardening |
Find the smallest axes-parallel square that contains at least one half of the given points.
Input files:
Easy input data set – G1,
Hard input data set – G2.
|
| Equatorial Bonfire |
A set of bonfires is started along the equator, find the time when all the equator is on fire.
Input files:
Easy input data set – H1,
Hard input data set – H2.
Solutions:
Correct output – H1,
Correct output – H2.
|
| IPSC 2002 practice session | |
| K-In-A-Row |
Compute the score for a given game of k-in-a-row.
Input files:
Easy input data set – R1,
Hard input data set – R2.
|
| Candy |
Redistribute candy between packets.
Input files:
Easy input data set – S1,
Hard input data set – S2.
|
| Ice Cream |
Find one Hamiltonian path in a tournament graph.
Input files:
Easy input data set – T1,
Hard input data set – T2.
|
| IPSC 2001 | |
| Andrew's Exams II |
Find the integer printed by an obfuscated program outputs.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Bacteria |
Interactively find a separating line between red and green points.
Input files:
Easy input data set – B1,
Hard input data set – B2.
Solutions:
Solution.
|
| Candies |
Separate three candy flavors by moving as few of them as possible.
Input files:
Easy input data set – C1,
Hard input data set – C2.
|
| Urvi Komu Urvi |
Divide employees into two equal teams, maximizing the number of times a person plays against their boss.
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| A Censored Smile |
Count all smiling faces in a large picture.
Input files:
Easy input data set – E1,
Hard input data set – E2.
|
| Pibonacci |
Compute the elements of a Fibonacci-like sequence.
Input files:
Easy input data set – F1,
Hard input data set – F2.
Solutions:
Correct output – F1,
Correct output – F2.
|
| Gossipers |
Check whether all gossipers know everything at the end of the day.
Input files:
Easy input data set – G1,
Hard input data set – G2.
|
| Magic |
Find a suitable bijection between two sets of card decks.
Input files:
Easy input data set – H1,
Hard input data set – H2.
|
| IPSC 2001 practice session | |
| Strange Currency |
Find the largest sum that cannot be paid using given banknotes.
Input files:
Easy input data set – R1,
Hard input data set – R2.
Solutions:
Correct output – R1,
Correct output – R2.
|
| Santo's Apples and Banto's Pears |
Divide a garden into two equal parts, each containing trees of a single type.
Input files:
Easy input data set – S1,
Hard input data set – S2.
Solutions:
Correct output – S1,
Correct output – S2.
|
| IPSC 2000 | |
| K-In-A-Row |
Compute the score for a given game of k-in-a-row.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Cake |
Given a set of lines, count into how many parts they divide the plane.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Trolls |
Given a string, interactively guess its correct substring based on its number of occurrences.
Input files:
Easy input data set – C1,
Hard input data set – C2.
|
| Get Back! |
Travel between oases using as little water as possible.
Input files:
Easy input data set – D1,
Hard input data set – D2.
Solutions:
Correct output – D1,
Correct output – D2.
|
| Andrew's Exams |
Count the number of stars an obfuscated program outputs.
Input files:
Easy input data set – E1,
Hard input data set – E2.
|
| Puzzle |
Transform a 0/1 rectangle from one state to another by negating rows and exchanging columns.
Input files:
Easy input data set – F1,
Hard input data set – F2.
|
| Windy Office |
Reconstruct the page order of a program listing, knowing which pages contain which procedures.
Input files:
Easy input data set – G1,
Hard input data set – G2.
Solutions:
Correct output – G1,
Correct output – G2.
|
| Colorful Cubes |
Given cubes with colored sides, assemble a tower in which pairs of touching sides match.
Input files:
Easy input data set – H1,
Hard input data set – H2.
Solutions:
Correct output – H1,
Correct output – H2.
|
| IPSC 2000 practice session | |
| Santo's Bottles |
From a row of bottles, drink as much as possible without drinking from three consecutive bottles.
Input files:
Easy input data set – R1,
Hard input data set – R2.
Solutions:
Solution,
Program solving both data sets.
|
| Labyrinth |
Simulate a robot in a simple maze.
Input files:
Easy input data set – S1,
Hard input data set – S2.
|
| Coins |
Find counterexamples for greedy algorithms.
Input files:
Easy input data set – T1,
Hard input data set – T2.
|
| IPSC 1999 | |
| Billboard |
Find a 3-coloring of the given graph.
Input files:
Easy input data set – A1,
Hard input data set – A2.
|
| Candy |
Redistribute candy between packets.
Input files:
Easy input data set – B1,
Hard input data set – B2.
|
| Coins |
Find counterexamples for greedy algorithms.
Input files:
Easy input data set – C1,
Hard input data set – C2.
|
| Factorial |
Find the last non-zero digit of a factorial.
Input files:
Easy input data set – D1,
Hard input data set – D2.
|
| Labyrinth |
Simulate a robot in a simple maze.
Input files:
Easy input data set – E1,
Hard input data set – E2.
|
| Panel |
Switch rows and columns of bulbs to minimize the number of lit ones.
Input files:
Easy input data set – F1,
Hard input data set – F2.
|
| Rain |
For a given sequence, find the largest k such that no k-element subsequence has a too large sum.
Input files:
Easy input data set – G1,
Hard input data set – G2.
|
| Romeo |
Find out whether two people can meet when following shortest paths.
Input files:
Easy input data set – H1,
Hard input data set – H2.
|
| IPSC 1999 practice session | |
| Medical Research |
Given a sequence of numbers, answer queries about the k-th smalest one.
Input files:
Easy input data set – J1,
Hard input data set – J2.
|
