Common constraint programming problems

Below are the problems which I have implemented in at least two Constraint Programming systems. For more about these systems see the following links. The number shows the (approximate) number of models implemented in the system. Notes: Currently there are 449 problems implemented in at least 2 CP systems. There are 2495 implemented models. (Total implemented models, including those not showed here, is about 3840.)

Occurrences of problems

Here is the distribution of the number of implementations:

Learning problems

The following (about 161) problems are often the first problems that is modelled when learning a new Constraint Programming system. Here are shown those that has been implemented in at least 6 systems:

Common problem

Problem: 17_b (5)

Problem: 17_b3 (3)

Problem: 1d_rubiks_cube 1D Rubik's cube (including GAP code for solving the problem using group theory) [Puzzle] (3)

Problem: 3_jugs 3 jugs problem (as shortest path problem) [Puzzle] (7)

Problem: 3_jugs2 3 jugs problem (using shortest_path_model. [Puzzle] (3)

Problem: 3_jugs_regular (2)

Problem: 3sum 3SUM problem (general approach) [Combinatorial] (2)

Problem: 50_puzzle Fifty puzzle [Martin Chlond IP] (3)

Problem: 5x5_puzzle (2)

Problem: 99_bottles_of_beer 99 bottles of beer (Rosetta code) [Martin Chlond IP] (2)

Problem: abbots_puzzle (7)

Problem: abbott The Abbott's Window [Martin Chlond IP] (3)

Problem: abc_endview ABC End View grid puzzle (a.k.a. "Easy as ABC", "Last Man Standing") [Puzzle] (3)

Problem: added_corner Added corner puzzle [Puzzle] (8)

Problem: alldifferent_cst alldifferent_cst, and alldifferent_cst using multiplication instead of addition [Global constraint] (6)

Problem: alldifferent_except_0 (20)

Problem: alldifferentexcept0 (5)

Problem: alldifferent_modulo alldifferent_modulo, all values modulo k shall be different [Global constraint] (6)

Problem: alldifferent_on_intersection alldifferent_on_intersection [Global constraint] (5)

Problem: all_differ_from_at_least_k_pos all_differ_from_at_least_k_pos, all rows in a matrix has values that differs in at least k positions [Global constraint] (6)

Problem: alldiff_test (2)

Problem: all_equal (5)

Problem: all_interval All interval problem (series), (CSPLib problem 7) [Combinatorial] (17)

Problem: allintervals (2)

Problem: all_min_dist all_min_dist, all pairs in an array have a distance of at least c [Global constraint] (6)

Problem: allpartitions (4)

Problem: alpha (3)

Problem: alphametic (5)

Problem: among (7)

Problem: among_seq among_seq [Global constraint] (8)

Problem: appointment_scheduling (4)

Problem: appointment_scheduling_set A set based approach to the appoiintment scheduling problem (see above). [Combinatorial] (3)

Problem: a_puzzle (7)

Problem: arch_friends Arch friends puzzle (Dell Logic Puzzles)" [Puzzle] (10)

Problem: a_round_of_golf A round of golf puzzle (Dell Logic Puzzles) [Puzzle] (14)

Problem: assignment Assignment problem (Winston) [OR] (16)

Problem: assignment2 Assignment problem (Winston's swimming team example) [OR] (4)

Problem: assignment3 Assigment problem (Winston, celebreties on an island) [OR] (3)

Problem: assignment6 Assigment problem (GLPK:s example assign.mod) [OR] (2)

Problem: autoref Auto referential puzzle [Puzzle] (3)

Problem: average_avoiding (2)

Problem: averbach_1.2 Example 1.2 in Averbach & Chein "Problem Solving Through Recreational Mathematics" [Puzzle] (6)

Problem: averbach_1.3 Example 1.3 in Averbach & Chein "Problem Solving Through Recreational Mathematics" [Puzzle] (6)

Problem: averbach_1.4 Example 1.4 in Averbach & Chein "Problem Solving Through Recreational Mathematics" [Puzzle] (9)

Problem: babysitting Babysitting puzzle (Dell Logic Puzzles) [Puzzle] (7)

Problem: balanced_brackets Generate balanced brackets [Combinatorial] (2)

Problem: bales_of_hay Bales of hay puzzle [Puzzle] (9)

Problem: bananas Bananas problem. [Puzzle] (3)

Problem: best_host Best host problem (from PuzzlOR) [OR] (5)

Problem: best_shuffle (2)

Problem: big_bang2 (3)

Problem: bin_packing (5)

Problem: bin_packing2 Bin packing (different from the one above) [Combinatorial] (6)

Problem: birthdays_coins Tommy's Birthday Coins [Martin Chlond IP] (3)

Problem: blending Blending problem (OPL) [OR] (4)

Problem: book_buy Book buy puzzle [Martin Chlond IP] (3)

Problem: bowlsandoranges (3)

Problem: box (2)

Problem: breaking_news Breaking news puzzle (Dell Logic Puzzles) [Puzzle] (9)

Problem: broken_weights Broken weights problem [Puzzle] (12)

Problem: build_a_house (4)

Problem: building_a_house Simple scheduling problem: building a house (from OPL) [OR] (5)

Problem: building_blocks Building blocks (Dell Logic Puzzles) [Puzzle] (7)

Problem: bus_schedule (12)

Problem: bus_scheduling Bus scheduling (Taha) [OR] (3)

Problem: bus_scheduling_csplib Bus driver scheduling (CSPLib problem 22). Data files: [OR] (2)

Problem: calculs_d_enfer Calculs d'enfer puzzle (from the NCL manual) [Puzzle] (15)

Problem: calvin_puzzle Calvin puzzle [Puzzle] (3)

Problem: candies Candies problem (from HackerRank) [Puzzle] (2)

Problem: capital_budget2 Capital Budget (Winston) [OR] (2)

Problem: car Car sequencing problem (OPL) [Combinatorial] (8)

Problem: catalan_numbers Catalan numbers [Martin Chlond IP] (2)

Problem: changes (5)

Problem: chessset Chess set problem (XPress) [OR] (3)

Problem: chinese_remainder_problem Chinese remainder problem [Martin Chlond IP] (2)

Problem: circling_squares Circling the Squares (Dudeney) [Nonlinear] (7)

Problem: circuit (11)

Problem: circuit2 (2)

Problem: circuittest circuit [Global constraint] (4)

Problem: clique clique [Global constraint] (7)

Problem: clock_triplet (4)

Problem: clocktriplet Clock Triplets [Global constraint] (4)

Problem: coins Coin puzzle [Martin Chlond IP] (2)

Problem: coins3 Minimum mumber of coins that allows one to pay exactly any amount smaller than one Euro [Puzzle] (13)

Problem: coins_grid Coins Grid (Tony Hurlimann) [Puzzle] (23)

Problem: collatz Collatz problem [Martin Chlond IP] (2)

Problem: color Map coloring, Martin Gardner's coloring problem (BProlog) [Global constraint] (2)

Problem: coloring_ip Map coloring, integer programming (inspired by the GLPK model color.mod) [OR] (2)

Problem: color_simple Simple coloring of a map (Murty) [Combinatorial] (2)

Problem: combinatorial_auction Simple combinatorial auction problem (compare with the set covering/set partition problem in (9)

Problem: combinatorialauction Simple combinatorial auction problem (compare with the set covering/set partition problem in (4)

Problem: contiguity_regular global_contiguity (using regular constraint) [Global constraint] (4)

Problem: contracting_costs (5)

Problem: costas_array Costas array (based on Barry O'Sullivan's model) [Combinatorial] (9)

Problem: covering_opl (14)

Problem: crew Crew scheduling (Gecode) [OR] (12)

Problem: critical_path1 Critical Path (Winston) [OR] (2)

Problem: crossbar Crossbar problem (Prolog benchmark problem) [OR] (2)

Problem: crossfigure Crossfigure problem (CSPLib problem 21) [Puzzle] (5)

Problem: crossword Crossword solving (standard constraint programming example) [Puzzle] (12)

Problem: crossword2 Crossword solving (standard constraint programming example), more general approach [Puzzle] (10)

Problem: crosswords (2)

Problem: crosswords2 (2)

Problem: crowd The crowded board [Martin Chlond IP] (3)

Problem: crypta crypta, alphametic problem (standard Prolog benchmark) [Puzzle] (11)

Problem: crypto crypto, alphametic problem (standard Prolog benchmark), constraint programming model [Puzzle] (10)

Problem: cumulative_test Test of cumulative (defined in globals. [Global constraint] (5)

Problem: curious_set_of_integers Curious set of integers [Global constraint] (9)

Problem: cur_num Curious Number (Dudeney) [Puzzle] (8)

Problem: cutting_stock_winston Cutting stock problem (Winston) [OR] (2)

Problem: cyclohexane Cyclohexane problem (Dudeney) [Nonlinear] (2)

Problem: dakota_furniture (2)

Problem: debruijnbinary de Bruijn sequence (graph) [Combinatorial] (19)

Problem: debruijn_binary de Bruijn sequence (graph) [Combinatorial] (4)

Problem: defending_castle Defending the Castle (Cut the knot) [Puzzle] (2)

Problem: devils_word (8)

Problem: diet (15)

Problem: diet Diet problem (standard OR example) [OR] (8)

Problem: diet2 Diet problem, larger (GLPK example) [OR] (3)

Problem: dinner A dinner problem [Puzzle] (7)

Problem: discrete_tomography (14)

Problem: distribute (6)

Problem: divisible_by_9_through_1 divisible by 9 through 1 for a "truncated" number [Puzzle] (15)

Problem: donald_gerald (5)

Problem: dqueens (3)

Problem: drive_ya_nuts Drive Ya Nuts puzzle (rotated "nuts") [Puzzle] (4)

Problem: dudeney (3)

Problem: dudeney_bishop_placement1 Dudeney's bishop placement problem I [Martin Chlond IP] (3)

Problem: dudeney_bishop_placement2 Dudeney's bishop placement problem II [Martin Chlond IP] (3)

Problem: dudeney_numbers (5)

Problem: dynamical_optimization1 Dynamical optimization [Nonlinear] (2)

Problem: earthlin Earthlings [Martin Chlond IP] (2)

Problem: egg_basket Egg basket puzzle [Martin Chlond IP] (3)

Problem: einav_puzzle (8)

Problem: einav_puzzle2 (2)

Problem: einstein_hurlimann Einstein puzzle (variant of Zebra puzzle) [Puzzle] (3)

Problem: einstein_opl Einstein puzzle (variant of Zebra puzzle, from an OPL model) [Puzzle] (5)

Problem: element_test (4)

Problem: enigma Enigma [Martin Chlond IP] (2)

Problem: eq10 Problem with 10 equation (standard constraint programming problem) [Nonlinear] (9)

Problem: eq20 (8)

Problem: equation Solve the problem 11x11=4; 22x22=16; 33x33=? (four interpretations) [Puzzle] (3)

Problem: euler1 Project Euler problem #1 [Puzzle] (4)

Problem: euler10 (2)

Problem: euler11 (2)

Problem: euler18 Project Euler problem #18 [Puzzle] (2)

Problem: euler2 Project Euler problem #2 [Puzzle] (4)

Problem: euler3 (2)

Problem: euler_30 Project Euler problem #30 [Puzzle] (2)

Problem: euler31 Project Euler problem #31 [Puzzle] (2)

Problem: euler39 Project Euler problem #39 [Puzzle] (2)

Problem: euler4 (2)

Problem: euler5 Project Euler problem #5 [Puzzle] (3)

Problem: euler6 Project Euler problem #6 [Puzzle] (3)

Problem: euler7 (2)

Problem: euler8 (2)

Problem: euler9 Project Euler problem #9 [Puzzle] (3)

Problem: evens (slightly different approach: (3)

Problem: evision Equal Vision [Martin Chlond IP] (2)

Problem: exactly (3)

Problem: exodus Exodus problem (Dell Logic Puzzle) [Puzzle] (7)

Problem: eyedrop_optimize2 Optimize the time (hour) a number of different eye drops should be taken on a day (disperse each type as much as possible). This version don't use temporary varibles which makes it (much) faster for some solvers. [OR] (2)

Problem: fancy Mr Greenguest puzzle (Fancy dress puzzle) [Puzzle] (8)

Problem: fib (2)

Problem: fill_a_pix Fill-a-pix puzzle.
[Puzzle] (12)

Problem: fill_in_the_squares Fill in the squares (Brainjammer problem) [Puzzle] (5)

Problem: finding_celebrities Finding celebrities at a party (indicence matrix). [Combinatorial] (4)

Problem: finding_celebrities2 Finding celebrities at a party, using only set constraints. [Combinatorial] (2)

Problem: five (alternative model: (3)

Problem: five_brigands (5)

Problem: five_elements Five elements problem (Charles W. Trigg) [Puzzle] (3)

Problem: five_floors Five floors problem (Dinesman) [Puzzle] (4)

Problem: five_statements Five statements problem (logic problem) [Puzzle] (2)

Problem: fixed_charge Fixed charged problem (OPL) [OR] (3)

Problem: fizz_buzz Fizz buzz problem [Martin Chlond IP] (2)

Problem: four_islands Four islands puzzle (Dell Logic Puzzles) [Puzzle] (9)

Problem: four_numbers Four numbers problem (Stack overflow) [Puzzle] (2)

Problem: fractions Fractions, alphametic problem (standard Prolog benchmark) [Puzzle] (7)

Problem: furnituremovingtransition Optimizing furniture moving (Marriott and Stuckey) [OR] (17)

Problem: furniture_moving2 (3)

Problem: futoshiki Futoshiki puzzle [Puzzle] (12)

Problem: games Simple game theory example (Vanderbei "Linear Programming - Foundations - and Extensions", page 147ff) [OR] (2)

Problem: game_theory_taha Game theory, zero sum game (Taha, Operations Research) [OR] (6)

Problem: gcc_test (2)

Problem: general_store General store problem (Sam Loyd) [Puzzle] (7)

Problem: giapetto Simple optimization problem of maximizing profit [OR] (2)

Problem: global_cardinality (4)

Problem: global_contiguity global_contiguity [Global constraint] (7)

Problem: global_contiguity2 global_contiguity (different approach) [Global constraint] (2)

Problem: golomb_ruler (6)

Problem: gray_code Gray code [Combinatorial] (2)

Problem: greatest_subsequential_sum (2)

Problem: grid17x17 (2)

Problem: grocery (7)

Problem: hamming_distance Hamming distance [Combinatorial] (7)

Problem: handshaking Halmo's handshake problem [Puzzle] (4)

Problem: hanging_weights Hanging weights puzzle [Puzzle] (5)

Problem: heterosquare Heterosquare problem [Puzzle] (7)

Problem: hidato Hidato puzzle [Puzzle] (15)

Problem: hidato_table Hidato puzzle, using a table constraint. [Puzzle] (5)

Problem: hitchcock_transporation_problem Hitchcock-Koopmans transportation problem [OR] (2)

Problem: honey_division Honey division puzzle [Martin Chlond IP] (3)

Problem: house2 (2)

Problem: huey_dewey_louie Huey, Dewey, Louie, logical problem from Marriott & Stuckey "Programming in Constraints" [Puzzle] (7)

Problem: inverse (4)

Problem: isbn Some explorations in ISBN-13 [Martin Chlond IP] (9)

Problem: jive_turkeys Jive turkeys [Martin Chlond IP] (3)

Problem: jobs_puzzle Jobs puzzle (an automated reasoning problem) [Puzzle] (8)

Problem: joshua Joshua and his rats [Martin Chlond IP] (2)

Problem: just_forgotten Just forgotten puzzle (Enigma 1517) [Puzzle] (13)

Problem: k4p2gracefulgraph2 K4P2 Graceful Graph (more general model) [Combinatorial] (6)

Problem: kakuro Kakuro puzzle [Puzzle] (13)

Problem: kakuro2 Kakuro puzzle, alternative representation of the hints. [Puzzle] (4)

Problem: kenken2 KenKen puzzle [Puzzle] (12)

Problem: killer_sudoku Killer Sudoku puzzle [Puzzle] (14)

Problem: knapsack (6)

Problem: knapsack2 Another knapsack problem [Combinatorial] (2)

Problem: knapsack_investments Knapsack (investment) problem (Lundgren, Rönnqvist, Värbrand: Optimeringslära) [OR] (6)

Problem: knapsack_rosetta_code_01 Knapsack problem, 0/1 (Rosetta code) [Combinatorial] (4)

Problem: knapsack_rosetta_code_bounded Knapsack problem, bounded (Rosetta code) [Combinatorial] (4)

Problem: knapsack_rosetta_code_unbounded Knapsack problem (float), Unbounded (Rosetta code) [Combinatorial] (2)

Problem: knapsack_rosetta_code_unbounded_int Knapsack problem Unbounded, integer version of (2)

Problem: knights_path (3)

Problem: kntdom Knight domination puzzle - all squares threatened [Martin Chlond IP] (2)

Problem: kqueens Kraitchik's queen placement problem [Martin Chlond IP] (2)

Problem: krypto Krypto puzzle (combine given numbers to an objective using the four basic arithmetic operations) [Puzzle] (2)

Problem: labeled_dice (14)

Problem: labeled_dice2 (2)

Problem: langford (15)

Problem: langford2 Langford's number problem (CSPLib problem 24) [Combinatorial] (2)

Problem: latin_square_card_puzzle Latin square card puzzle [Puzzle] (3)

Problem: latin_squares (5)

Problem: lccoin Lewis Carroll coin puzzle [Martin Chlond IP] (2)

Problem: leastdiff2 Least diff problem: What is the smallest difference between two numbers X - Y if you must use all the digits (0..9) exactly once? [Puzzle] (19)

Problem: leastdiff2 (7)

Problem: least_square (2)

Problem: least_square_optimeringslara_286 Least sqauare (Lundgren, Rönnqvist, Värbrand: Optimeringslära) [OR] (2)

Problem: lectures Lectures, schedule problem from Biggs "Discrete Mathematics" [Combinatorial] (11)

Problem: lecture_series Lecture series puzzle (Dell Logic Puzzles) [Puzzle] (7)

Problem: lichtenstein_coloring Coloring problem: Lichtenstein's communes and exclaves [Combinatorial] (7)

Problem: lights Lights on puzzle [Martin Chlond IP] (2)

Problem: local_art_theft Local Art Theft problem. [Puzzle] (2)

Problem: m12 (2)

Problem: magic Magic square, integer programming (GLPK) [Puzzle] (2)

Problem: magic_hexagon (9)

Problem: magic_sequence Magic sequence (CSPLib) [Puzzle] (10)

Problem: magic_square Magic squares [Puzzle] (12)

Problem: magicsquare2 (2)

Problem: magic_square_and_cards (7)

Problem: magic_squares_and_cards Magic squares and cards [Global constraint] (2)

Problem: magicsquarewaterretention Magic squares water retention problem [Puzzle] (3)

Problem: magic_venn_diagram (2)

Problem: mamas_age Mama's age (Dudeney) [Puzzle] (6)

Problem: mango_puzzle Mango puzzle [Martin Chlond IP] (2)

Problem: mankell (4)

Problem: map Simple coloring of a map [Combinatorial] (13)

Problem: map2 Simple coloring of a map (using symmetry breaking with precedence/1) [Combinatorial] (6)

Problem: map_coloring (7)

Problem: map_coloring2 (2)

Problem: marathon Marathon puzzle (XPress example), MIP model [Puzzle] (5)

Problem: marathon2 Marathon puzzle (XPress example), CP model [Puzzle] (12)

Problem: maxflow Maximum flow problem (GLPK) [OR] (2)

Problem: max_flow_taha Maximum flow problem (Taha) [OR] (6)

Problem: max_flow_winston1 Maximum flow problem (Winston) [OR] (8)

Problem: message_sending Message sending puzzle (cf all_paths_graph. [Puzzle] (2)

Problem: minesweeper Minesweeper puzzle [Puzzle] (23)

Problem: minesweeper2 minesweeper_2. [Puzzle] (2)

Problem: minsum Minsum problem [Combinatorial] (2)

Problem: miss_manners Miss Manners' seating problem (standard benchmark for rule engines). Data: [Puzzle] (3)

Problem: mod_test (2)

Problem: money_change Simple money change problem [Puzzle] (4)

Problem: monks_and_doors Eight monks and four doors [Puzzle] (7)

Problem: mortgage Mortgage (standard constraint programming problem) [Nonlinear] (2)

Problem: movement_puzzle Movement puzzle (1d array) [Puzzle] (2)

Problem: mr_smith Mr Smith problem (IF Prolog) [Puzzle] (12)

Problem: multiplicative_sequence Multiplicative sequence [Puzzle] (2)

Problem: music_men Music men puzzle [Puzzle] (6)

Problem: nadel B.A. Nadel's construction problem [OR] (6)

Problem: nim (2)

Problem: non_dominating_queens Non-dominating queens problem [Martin Chlond IP] (2)

Problem: nonogram Nonogram, a. [Puzzle] (4)

Problem: nonogram_regular Nongoram, a. [Puzzle] (3)

Problem: nontransitive_dice Nontransitive dice [Combinatorial] (8)

Problem: nqueens (7)

Problem: nqueens2 (5)

Problem: number_of_days Number of days problem (knapsack) [OR] (6)

Problem: number_square Recreational mathematics (Pascal Van Hentenryck: "The OPL Optimization Programming Language") [Puzzle] (3)

Problem: nurse_rostering_regular (2)

Problem: nvalue (3)

Problem: nvalues nvalues [Global constraint] (4)

Problem: olympic Olympic problem (standard Prolog benchmark) [Puzzle] (11)

Problem: onroad On the road [Martin Chlond IP] (2)

Problem: organize_day Scheduling, organizing a day (ECLiPSe) [OR] (12)

Problem: ormat_game (6)

Problem: pair_divides_the_sum Pair divides the sum problem [Puzzle] (5)

Problem: pandigital_numbers Pandigital numbers (any base <= 10) [Puzzle] (12)

Problem: partition_into_subset_of_equal_values (2)

Problem: partition_into_subsets_of_equal_values (4)

Problem: partitionintosubsetsofequalvalues2 (2)

Problem: penguin Nonmonotonic reasoning: can Tweety - a penguin - fly? (Alma-0) [Martin Chlond IP] (2)

Problem: perfect_shuffle Perfect shuffle [Combinatorial] (2)

Problem: perfectsquare (2)

Problem: perfect_square_placement (2)

Problem: perfect_square_sequence Perfect square sequence [Puzzle] (6)

Problem: pert PERT problem (van Hentenryck) [OR] (7)

Problem: photo_problem (11)

Problem: picking_teams Picking teams (where the objective is to minimize the differences in total strength of each team). [Combinatorial] (5)

Problem: picking_teams2 (2)

Problem: pigeon_hole Pigeon hole problem (CLP-FD) [Combinatorial] (8)

Problem: pilgrim The Riddle of the Pilgrims [Martin Chlond IP] (2)

Problem: place_number Placing Number Puzzle [Puzzle] (3)

Problem: place_number_puzzle (13)

Problem: p_median P-median problem (OPL) [OR] (8)

Problem: post_office_problem Post office problem (Winston) [OR] (4)

Problem: post_office_problem2 Post office problem, generalized model (Winston) [OR] (10)

Problem: primes_in_a_circle Primes in a circle [Puzzle] (2)

Problem: production (2)

Problem: public_school_problem Public School Problem [Martin Chlond IP] (2)

Problem: puzzle1 Yet another column/row sum problem [Puzzle] (2)

Problem: pythagoras Pythagoras number [Martin Chlond IP] (6)

Problem: quasigroup_completion Quasigroup completion problem [Combinatorial] (24)

Problem: queens (3)

Problem: rabbits (6)

Problem: regular (2)

Problem: remainder_puzzle (alternative model: (2)

Problem: remainder_puzzle2 (2)

Problem: remainders (5)

Problem: remarkable_sequence Remarkable sequence (from an Alma-0 model) [Puzzle] (5)

Problem: reverse_multiples Reverse multiples [Puzzle] (2)

Problem: rogo Rogo grid puzzle, (2)

Problem: rogo2 (6)

Problem: rot13 Rot 13 (Caesar) cipher [Martin Chlond IP] (4)

Problem: rotation Nokia's "rotation puzzle" [Puzzle] (2)

Problem: runs Number of runs in an array (sequence) [Combinatorial] (2)

Problem: safe_cracking Safe cracking [Puzzle] (11)

Problem: sat Satisfiability Problem, integer programming (GLPK) [Combinatorial] (2)

Problem: scene_allocation (3)

Problem: schedule1 Scheduling using cumulative constraint (Sicstus) [OR] (6)

Problem: schedule2 Scheduling problem, yet another (from Shasha "Puzzles for Programmers and Pros", page 131f) [OR] (4)

Problem: scheduling_speakers Scheduling speakers (Rina Dechter) [OR] (13)

Problem: scheduling_speakers_optimize (3)

Problem: scheduling_speakers_optimize2 (2)

Problem: scheduling_test (2)

Problem: schur_numbers (2)

Problem: secret_santa Secret Santa problem [Puzzle] (9)

Problem: secret_santa2 Another Secret Santa problem [Puzzle] (7)

Problem: send_more_money Alphametic puzzle: SEND + MORE = MONEY [Puzzle] (11)

Problem: sendmoremoney2 Alphametic puzzle: SEND + MORE = MONEY, alternative model [Puzzle] (8)

Problem: send_more_money_any_base Alphametic puzzle: SEND + MORE = MONEY, in any base [Puzzle] (16)

Problem: send_most_money Alphametic puzzle: SEND + MOST = MONEY (maximize MONEY) [Puzzle] (18)

Problem: send_most_money2 (3)

Problem: sequence (4)

Problem: sequencesum (2)

Problem: seseman (24)

Problem: seseman2 Seseman Convent problem, generalized model [Puzzle] (2)

Problem: set_covering Set covering, placing of firestations (Winston) [Combinatorial] (16)

Problem: set_covering2 Set covering, number of security telephons on a campus (Taha) [Combinatorial] (15)

Problem: set_covering3 Set covering, senators making a committe (Murty) [Combinatorial] (16)

Problem: set_covering4 Set covering problem (Lundgren, Rönnqvist, Värbrand "Optimeringslära") [Combinatorial] (16)

Problem: set_covering5 Set covering, work scheduling (Lundgren, Rönnqvist, Värbrand "Optimeringslära") [Combinatorial] (5)

Problem: set_covering6 (2)

Problem: set_covering_deployment Set covering deployment [Combinatorial] (16)

Problem: set_covering_opl Set covering (OPL) [Combinatorial] (4)

Problem: set_covering_skiena Set covering (Skiena) [Combinatorial] (12)

Problem: set_packing Set packing [Combinatorial] (2)

Problem: set_partition Set partitioning [Combinatorial] (13)

Problem: seven11 (2)

Problem: shopping_basket6 Optimize a shopping basket with delivery costs. [OR] (3)

Problem: shortest_path1 Shortest path problem, selling/buying a car (Winston) [Combinatorial] (2)

Problem: shortest_path2 Shortest path problem (Winston) [Combinatorial] (3)

Problem: sicherman_dice Sicherman dice problem [Combinatorial] (12)

Problem: ski_assignment (14)

Problem: ski_assignment_problem Ski assignment problem [OR] (2)

Problem: sliding_sum (6)

Problem: smuggler_knapsack Smuggler's knapsack (Marriott and Stuckey: "Programming with Constraints") [Combinatorial] (4)

Problem: smugglers_knapsack (2)

Problem: smullyan_portia Raymond Smullyan's Portia problems [Puzzle] (2)

Problem: social_golfers1 Social golfers (OPL) [OR] (4)

Problem: social_golfers2 (3)

Problem: sonet (3)

Problem: sonet_problem SONET problem [Combinatorial] (4)

Problem: spreadsheet Simple spreadsheet problem [Martin Chlond IP] (5)

Problem: square_root_of_wonderful Square Root of Wonderful [Global constraint] (3)

Problem: squeens Schuh's queen placement problem [Martin Chlond IP] (2)

Problem: stable_marriage Stable marriage [OR] (14)

Problem: stablemarriagerandom (2)

Problem: stamp_licking The gentle art of stamp-licking [Martin Chlond IP] (2)

Problem: steiner (5)

Problem: stigler Original Stigler's 1939 diet problem (GLPK) [OR] (3)

Problem: strimko (2)

Problem: strimko2 (13)

Problem: stuckey_seesaw Balancing on a seesaw (Marriot and Stuckey) [OR] (7)

Problem: subset_sum Subset sum (Murty) [Combinatorial] (15)

Problem: sudoku (11)

Problem: sudoku2 (4)

Problem: sudoku_4x4 (2)

Problem: sudoku_gcc Sudoku, using the global cardinality constraint.
[Puzzle] (3)

Problem: survo_puzzle Survo puzzle [Puzzle] (24)

Problem: table (3)

Problem: talisman_square Talisman Square [Puzzle] (7)

Problem: tea_mixing Dudeney's tea mixing problem [Martin Chlond IP] (2)

Problem: temporal_reasoning Temporal reasoning (Apt) [Combinatorial] (3)

Problem: the_family_puzzle (4)

Problem: tictactoe_avoidance (2)

Problem: timetable Timetable of courses (from Alma-0) [OR] (2)

Problem: timpkin Mrs Timpkin's age problem (Dudeney) [Puzzle] (7)

Problem: tobacco Clarke's tobacconist [Martin Chlond IP] (2)

Problem: tomography Discrete Tomography (one color model) [Puzzle] (5)

Problem: tonum (16)

Problem: torn_number Torn number puzzle (Dudeney) [Puzzle] (3)

Problem: torn_numbers (4)

Problem: tourist_site_competition Tourist site competition (Pierre Flener) [Combinatorial] (9)

Problem: traffic_lights Traffic lights problem (CSPLib problem 16) [Combinatorial] (14)

Problem: trains (3)

Problem: transp1 Transportation problem (OPL) [OR] (2)

Problem: transportation Transportation problem (ECLiPSe) [OR] (2)

Problem: transshipment Transshipment problem (Winston) [OR] (2)

Problem: trial1 The First Trial [Martin Chlond IP] (2)

Problem: trial2 The Second Trial [Martin Chlond IP] (2)

Problem: trial3 The Third Trial [Martin Chlond IP] (2)

Problem: trial4 The Fourth Trial [Martin Chlond IP] (2)

Problem: trial5 The Fifth Trial [Martin Chlond IP] (2)

Problem: trial6 The Sixth Trial [Martin Chlond IP] (2)

Problem: tsp Travelling Salesman Problem, integer programming (GLPK) [OR] (6)

Problem: tsp_circuit Travelling salesperson problem, using circuit predicate [Combinatorial] (3)

Problem: tunapalooza Tunapalooza puzzle (Dell Logic Puzzles) [Puzzle] (6)

Problem: twelve Twelve draughts puzzle [Martin Chlond IP] (2)

Problem: twin_letters Twin letters [Puzzle] (7)

Problem: urban_planning (2)

Problem: warehouse (6)

Problem: water_buckets1 Water bucket problem (generalized) [Puzzle] (2)

Problem: wedding_optimal_chart (4)

Problem: were2 Werewolves II [Martin Chlond IP] (2)

Problem: were4 Werewolves IV [Martin Chlond IP] (2)

Problem: who_killed_agatha Who killed agatha? (The Dreadsbury Mansion Murder Mystery, a automated reasoning problem) [Puzzle] (23)

Problem: whokilledagatha_element (2)

Problem: wine_cask_puzzle Wine cask puzzle [Martin Chlond IP] (2)

Problem: volsay Volsay problem (OPL) [Combinatorial] (5)

Problem: volsay1 (4)

Problem: volsay2 Volsay problem, with arrays (OPL) [Combinatorial] (8)

Problem: volsay3 Volsay problem, with components (OPL) [Combinatorial] (6)

Problem: word_golf Word golf (word chain) [Puzzle] (3)

Problem: word_square Word square: square matrix cross words (fill the whole square with unique words). [Puzzle] (12)

Problem: word_square2 (3)

Problem: word_square_double (2)

Problem: xkcd (22)

Problem: young_tableaux Young tableaux [Combinatorial] (21)

Problem: zebra (9)

Problem: zebra_1_5 (2)
By Hakan Kjellerstrand (
Also see: