TryAlgo

Selected problems

We selected a few problems, which we think are good training material for programming contests. Each problem is assigned to some category and also to some level. We recommend to start with level 1 in order to make sure you know the basic tools. Then continue with level 2, 3 and finally 4. But you already guessed this, right?

Show chapter hint.

difficultéproblèmeénoncé
Advanced ASCII Cubes [tju] [zju]
☆☆☆☆Australian Voting [tju]
☆☆☆☆Babel Towers [tju]
☆☆☆☆Blood Type [tju]
☆☆☆☆Bullseye [codejam]
City hall [tju]
☆☆☆☆Common Item [tju]
☆☆☆☆Cryptoquote [tju]
☆☆☆☆DNA Sorting [tju]
☆☆☆☆European railroad tracks [tju]
☆☆☆☆Giant Screen [tju]
☆☆☆☆Huffman Trees [tju] [zju]
☆☆☆☆Interpreter [tju]
☆☆☆☆Knights In The Zombie Land [onlinejudge]
LC Display [tju]
☆☆☆☆Matrix Swapping II [tju]
Mine Sweeper [tju]
☆☆☆Poker Hands [onlinejudge]
☆☆☆☆The Trip [tju]
☆☆☆☆Total flow [tju]
☆☆☆☆X-Express [onlinejudge]
☆☆Anagram checker [onlinejudge]
☆☆Anagram Groups [poj] [tju]
☆☆☆☆Factorvisors [onlinejudge]
☆☆☆☆Channel Allocation [tju]
☆☆☆☆Minimal length addition chain [codility]
☆☆Mirror Maze [onlinejudge]
☆☆Sudoku (16x16) [tju] [spoj]
☆☆Sudoku (9x9) [tju] [spoj]
☆☆☆☆The Triangle Game [zju]
☆☆☆☆Haunted graveyard [spoj]
☆☆Negative Cycles [spoj]
☆☆Roads in Berland [spoj]
☆☆Hike on a Graph [spoj]
☆☆☆☆Kisu Pari Na 2 [onlinejudge]
☆☆☆☆Knight Moves [poj]
☆☆Ricochet Robots [onlinejudge]
☆☆Traffic Jam [icpcarchive] [tju]
☆☆☆☆Street Directions [tju]
☆☆The Key Stations [tju]
☆☆☆☆AggressiveCows [spoj]
☆☆Egg Drop [codejam]
☆☆Fill the cisterns [spoj]
☆☆☆☆SpeedCameras [codility]
☆☆☆☆France'98 [uni-ulm] [uni-ulm]
☆☆☆☆Hexagonal Routes [tju]
☆☆Dungeon of Death [spoj]
☆☆Muddy Fields [spoj]
☆☆☆☆Playground [tju]
☆☆☆☆Make it Manhattan [tju]
☆☆The Ant [spoj]
☆☆☆☆Herding Frosh [tju]
☆☆Unique Encryption Keys [icpcarchive]
☆☆☆☆Alien Numbers [codejam]
☆☆☆☆All your base [codejam]
☆☆☆☆Crazy Search [tju]
☆☆☆☆IPNetworks [tju]
Problem 3467 [tju]
☆☆☆☆Caterpillar [tju]
☆☆Mine [tju]
☆☆☆☆Mine [tju]
☆☆Playing Boogle [onlinejudge]
☆☆☆☆Poor Wenwen [tju]
☆☆☆☆The Die Is Cast [tju]
☆☆☆☆Incidental Points [tju]
☆☆Almost the shortest route [tju]
☆☆☆☆Dirt [tju]
☆☆Dragon Maze [codejam]
☆☆☆☆Hydrogenium [codility]
☆☆☆☆Low Cost Air Travel [icpcarchive]
☆☆☆☆The K-th City [tju]
☆☆War [tju]
☆☆Stock Charts [codejam]
☆☆Taxi Cab Scheme [icpcarchive] [poj]
☆☆☆☆Wooden sticks [poj] [tju]
☆☆Fast Maximum Flow [spoj]
☆☆Maximum Flow [spoj]
☆☆A Famous Grid [spoj]
☆☆☆☆A Digging Problem [codejam]
☆☆☆☆Airbus vs. Boeing [onlinejudge]
☆☆☆☆Blocks [onlinejudge]
☆☆☆☆Brackets sequence [tju]
☆☆☆☆Bribe the Prisoners [codejam]
☆☆☆☆Chopstick [onlinejudge]
☆☆☆☆Cow Solitaire [tju]
☆☆Sweet and Sour Rock [spoj]
☆☆☆☆To The Max [tju]
☆☆The Spiral of Primes [icpcarchive]
☆☆Free Tour [spoj]
☆☆Goldbach graphs [spoj]
☆☆☆☆Alien Language [codejam]
☆☆Boolean Expression [tju]
☆☆Cells [spoj]
☆☆☆☆Compile Error [spoj]
☆☆☆☆Matrix Chain Multiplication [poj]
☆☆☆☆Simplified Lambda-evaluations [tju]
☆☆Spreadsheet [onlinejudge] [tju]
☆☆☆Strange Expression [tju]
☆☆Modex [onlinejudge]
☆☆Tiling a Grid With Dominoes [tju] [spoj]
☆☆☆☆Language recognition [onlinejudge]
☆☆☆☆Edgetown's Traffic Jams [onlinejudge]
☆☆☆☆Stockbroker Grapevine [tju]
☆☆☆☆Word Ladders [tju]
☆☆Stable Marriage Problem [spoj]
☆☆Ars Longa [onlinejudge] [icpcarchive]
Center of Mass [codejam]
☆☆☆☆Chocolate Chip Cookies [tju]
☆☆☆☆Divide the land [onlinejudge]
☆☆☆November Rain [poj] [tju]
☆☆☆☆Shrinking Polygons [icpcarchive]
☆☆Finding Nemo [tju] [zju]
☆☆☆☆Largest Submatrix of All 1’s [pku] [poj]
☆☆☆☆ABCD [spoj]
☆☆☆☆Airport Walkways [codejam]
Color A Tree [tju]
☆☆☆☆Enter the dragon [icpcarchive]
☆☆☆☆Feel Good [tju]
☆☆☆☆Flags [codility]
☆☆☆☆Homework [tju]
☆☆Minimal Coverage [onlinejudge]
☆☆Minimum Scalar Product [codejam]
Novice41 [spoj]
☆☆☆☆Prefix Suffix Set [codility]
☆☆☆☆Always Turn Left [codejam]
☆☆☆☆Number Steps [tju]
☆☆☆☆Spiral of Numbers [onlinejudge]
☆☆Huffman Trees [poj]
☆☆Variable Radix Huffman Encoding [spoj]
☆☆Radar Installation [tju]
☆☆4 Values whose Sum is 0 [poj]
☆☆A Needle in the Haystack [spoj]
☆☆Find the maximal product of string prefixes [codility]
☆☆Networking [tju]
☆☆Selfish Cities [spoj]
☆☆Advanced Edit Distance [spoj]
☆☆Edit distance [spoj]
☆☆The Separator in Grid [tju]
☆☆Common Subsequence [tju]
☆☆Longest Common Subsequence [spoj]
☆☆Easy Longest Increasing Subsequence [spoj]
☆☆☆☆Is Bigger Smarter? [tju]
☆☆☆☆Longest Ordered Subsequence [tju]
☆☆☆☆Ascending paths [codility]
☆☆☆☆Edit Step Ladders [tju]
☆☆☆☆Stacking Boxes [onlinejudge]
☆☆Labyrinth [spoj] [tju]
☆☆☆☆Labyrinth [tju]
☆☆Longest path in a tree [spoj]
☆☆☆☆Greatest Common Increasing Subsequence [tju] [pku]
☆☆City Driving [stanford] [stanford]
☆☆Casting Spells [icpcarchive]
☆☆Longest Palindrome [onlinejudge]
☆☆Mixtures [spoj]
☆☆Optimal Array Multiplication Sequence [tju]
☆☆The safe secret [onlinejudge]
☆☆Crime Wave [onlinejudge] [icpcarchive]
☆☆☆☆Down Went the Titanic [onlinejudge]
☆☆☆☆Magic Sticks Again [tju]
☆☆☆☆Councilling [onlinejudge]
☆☆☆☆Courses [tju]
☆☆☆☆Pizza Delivery [tju] [zju]
☆☆Word Rings [spoj]
☆☆Anagram [onlinejudge]
☆☆GREAT+SWERC=PORTO [onlinejudge]
☆☆☆☆Barcode of Judgment [livearchive]
☆☆☆☆Crypto Columns [tju]
☆☆Period [spoj]
☆☆Power strings [onlinejudge]
☆☆T9 [poj]
☆☆☆☆Phone Numbers [poj]
☆☆☆☆Freckles [onlinejudge]
☆☆☆☆Aerobics [codejam]
☆☆Tetris [tju]
☆☆Enormous Input Test [spoj]
☆☆☆☆Finding Seats [icpcarchive]
☆☆Largest Rectangle in a Histogram [tju]
☆☆☆☆Ultra Quick-Sort [tju]
☆☆Almost the shortest route [tju]
☆☆Heavy Cargo [tju]
☆☆☆☆Bot Trust [codejam]
☆☆☆☆Common Permutation [tju]
☆☆Disk Tree [tju]
Editor Nottobad [onlinejudge]
☆☆I am Lord Voldemort [tju]
Walk [tju]
☆☆☆☆What's Cryptanalysis? [onlinejudge]
Binary Trees [tju]
Insults [icpcarchive]
☆☆☆☆Excessive Space Remover [onlinejudge]
File Fragmentation [onlinejudge]
☆☆☆☆Java vs C++ [tju]
☆☆Capital City [spoj]
☆☆A concrete ad_hoc [spoj]
☆☆Encryption [spoj]
☆☆Havannah [codejam]
☆☆Phone List [spoj]
☆☆Boat Burglary [tju]
☆☆☆☆Stammering Aliens [spoj]
☆☆☆☆Line Segments [tju]
☆☆☆☆Rectilinear polygon [tju]
☆☆Retour vers le futur [prologin]
☆☆☆☆The Skyline Problem [onlinejudge]
☆☆☆☆Weird Advertisement [onlinejudge]
☆☆Ordering Tasks [onlinejudge]
☆☆Project File Dependencies [spoj]
☆☆Rare Order [onlinejudge]
☆☆Collecting Beepers [tju]
☆☆Spell checker [onlinejudge] [icpcarchive]
☆☆Manhattan [onlinejudge]
☆☆☆☆Seminar Room [tju]
☆☆Soldiers on Parade [spoj]
☆☆City Park [icpcarchive]
☆☆☆☆Heavy Transportation [poj] [tju]
☆☆☆☆Rectangles [tju]