Problems

Note that you can solve most task in any order!
Already solved ones are at the bottom of the table.

Volume:

Simple Implementation Algorithms Puzzles Special

all tags

Id	Title	Translations	Author	Solved	Blessing
1	Sum "A+B"	DE ES FR AR ZH RO RU SK		59267	1.00
2	Sum in Loop	DE ES FR AR ZH RO RU SK		35922	1.87
3	Sums in Loop	DE ES FR AR ZH RO RU SK		27373	2.34
4	Minimum of Two	DE ES FR AR ZH RO RU SK		23862	2.58
5	Minimum of Three	DE ES FR AR ZH RO RU SK		21359	2.77
15	Maximum of array	DE ES AR ZH RO RU SK		18657	3.01
6	Rounding	DE ES AR ZH RO RU SK		17102	3.16
7	Fahrenheit to Celsius	DE ES AR ZH RO RU SK		16379	3.23
20	Vowel Count	DE ES AR ZH RO RU SK		13283	3.60
11	Sum of digits	DE ES RU ZH SK		13223	3.61
8	Arithmetic Progression	DE ES RU ZH SK		12407	3.72
41	Median of Three	DE ES AR ZH RO RU SK		11352	3.87
9	Triangles	DE ES RU ZH SK		11863	3.79
28	Body Mass Index	DE ES ZH RU SK		11228	3.89
13	Weighted sum of digits	DE ES RU ZH SK		10707	3.97
43	Dice Rolling	DE ES ZH RU SK		9624	4.16
16	Average of an array	DE ES RU SK		10150	4.07
30	Reverse String	DE ES RU SK		9578	4.17
17	Array Checksum	DE ES RU SK		9420	4.19
21	Array Counters	DE ES RU SK		8768	4.32
10	Linear Function	DE ES RU SK		8524	4.37
48	Collatz Sequence	DE ES RU SK		7569	4.57
12	Modulo and time difference	DE ES RU SK		7717	4.54
14	Modular Calculator	ES SK		7145	4.68
27	Bubble Sort	ES RU SK		6453	4.85
26	Greatest Common Divisor	ES SK RU		6275	4.90
18	Square Root	ES RU		6113	4.95
29	Sort with Indexes	RU		5809	5.03
50	Palindromes	DE ES RU SK		5357	5.18
23	Bubble in Array	ES RU		5564	5.11
52	Pythagorean Theorem	RU		5154	5.24
31	Rotate String	ES RU		5319	5.19
67	Fibonacci Sequence	RU		4605	5.44
68	Bicycle Race	ES RU		4573	5.45
24	Neumann's Random Generator	DE ES RU		4948	5.31
57	Smoothing the Weather	ES RU		4563	5.45
35	Savings Calculator			4376	5.53
104	Triangle Area	ES		3668	5.83
25	Linear Congruential Generator	RU		4312	5.55
32	Josephus Problem	RU		4208	5.59
44	Double Dice Roll	RU		4071	5.65
81	Bit Count	RU		3656	5.84
19	Matching Brackets	ES RU		3959	5.70
58	Card Names			3485	5.92
47	Caesar Shift Cipher	SK		3548	5.89
49	Rock Paper Scissors			3528	5.90
128	Combinations Counting			2864	6.26
55	Matching Words			3400	5.96
94	Fool's Day 2014	SK		2988	6.19
59	Bulls and Cows			3092	6.13
61	Prime Numbers Generation	RU		3033	6.16
22	Two Printers	ES RU		3291	6.02
42	Blackjack Counting			2811	6.30
120	Selection Sort			2222	6.70
38	Quadratic Equation			2603	6.43
33	Parity Control	RU		2538	6.47
53	King and Queen			2280	6.66
34	Binary Search			2350	6.61
171	Tree Height Measurement			1584	7.29
37	Mortgage Calculator	ZH		2205	6.72
45	Cards Shuffling	ZH		2145	6.76
69	Fibonacci Divisibility			2009	6.88
63	Integer Factorization	ZH		1931	6.95
46	Tic-Tac-Toe	ZH		1980	6.90
62	Prime Ranges			1765	7.10
72	Funny Words Generator			1716	7.15
121	Insertion Sort			1486	7.40
75	Yacht or Dice Poker			1627	7.24
172	Cloud Altitude Measurement			1202	7.77
127	Anagrams			1349	7.57
39	Share Price Volatility			1645	7.23
134	Flying Text Screensaver			1244	7.71
156	Luhn Algorithm	SK		1089	7.94
114	Tricky Printing			1179	7.80
80	Duel Chances			1232	7.73
36	Code Guesser	UA		1306	7.63
74	Clock Hands			1158	7.83
135	Variable Length Code			977	8.13
105	Convex Polygon Area			1008	8.08
54	Pythagorean Triples			1134	7.87
73	Hexagonal Grid			1038	8.02
145	Modular Exponentiation			849	8.37
97	Girls and Pigs			930	8.22
116	Summing Up			858	8.36
181	Reverse Polish Notation			655	8.82
98	Azimuth at Treasure Island			806	8.46
187	Static Web Page			611	8.94
85	Rotation in 2D Space			813	8.45
122	QuickSort			735	8.62
51	Dungeons and Dragons Dice	UA		872	8.33
40	Paths in the Grid	UA		875	8.32
56	Life is Simple			841	8.39
188	Basics of HTML			582	9.03
66	Caesar Cipher Cracker			773	8.54
70	Most Frequent Word			761	8.56
88	Pitch and Notes			712	8.68
485	Magic 3		csfpython	13	15.51
487	Reduce and Equalise		csfpython	9	16.09
108	Star Medals			632	8.89
480	Coin Payments		csfpython	20	14.80
60	Sweet Harvest			697	8.72
95	Simple Linear Regression			639	8.87
87	Tree Builder			648	8.84
77	Point to Segment Distance			652	8.83
491	Lucky Number Scores		csfpython	2	18.18
86	Brainfuck Interpreter			595	8.99
211	Information Entropy			408	9.64
71	Fibonacci Divisibility Advanced			606	8.96
91	Game of 2048			571	9.06
428	Broken Keyboard			90	12.26
207	Suffix Array			397	9.69
101	Gradient Calculation			531	9.19
143	Extended Euclidean Algorithm			468	9.41
176	Say 100			423	9.58
82	Levenshtein Distance			539	9.16
191	Spaceship Weight Fraud			384	9.75
119	Brain Fibo			471	9.40
89	Instrument Tuner			501	9.29
195	Mul Two			368	9.82
206	Base-32 Encoding			353	9.90
64	Maze Pathfinder			525	9.21
79	Cycles Detection			490	9.33
476	Prime Vowel Count		csfpython	19	14.89
92	Binary Heap			458	9.44
131	Four Pics One Word			404	9.66
83	Graph Generator			450	9.47
301	Skyscraper Price			196	10.91
136	Variable Length Code Unpack			364	9.84
78	Bezier Curves			419	9.60
90	Lexicographic Permutations			405	9.66
189	Dynamic Web Page			305	10.15
150	Introducing Regexps			343	9.95
489	TV Charity Fundraiser		csfpython	3	17.68
492	Fastest Clearance		csfpython	-	20.09
126	Sequence of Squares			365	9.84
65	Transitive Closure on Candy States			416	9.61
167	Copy Line			310	10.12
170	Binary Search in Array			305	10.15
385	Number of steps in Euclidean Algorithm		gardengnome	101	12.06
154	Breadth First Search			318	10.08
461	Lucky 7		csfpython	29	14.18
481	Field Trip		csfpython	10	15.93
99	Uphill Shooting			359	9.87
197	Loops in Assembly			269	10.37
117	Divide by Two			335	9.99
144	Modular Inverse			301	10.17
377	Sum of Digits Divisibility			99	12.09
429	Moving Average in Time			54	13.13
174	Calculation of Pi			260	10.42
161	Topological Sorting			270	10.36
155	Depth First Search			273	10.34
76	Pawn Move Validator			335	9.99
425	Explosive Breeding			53	13.16
133	Billiard Ball			282	10.28
484	A Message from Deep Space		csfpython	6	16.71
165	Safe Landing			251	10.49
96	Snake Arcade			304	10.15
140	Proper Bracket Sequences			270	10.36
482	SS Numbers		csfpython	7	16.48
471	Missing Digits		csfpython	15	15.27
93	Starving Priority Queue			289	10.24
103	Easter Eggs			281	10.29
184	Matches Picking		quandray	221	10.71
123	Knapsack of Integers			264	10.40
472	Unreachable Amounts		csfpython	14	15.39
84	Dijkstra in the Network			289	10.24
444	White Rectangle			33	13.97
190	Query String Parameters			207	10.82
130	Combinations with Repetitions			248	10.51
173	Chords of Music			217	10.74
125	Bogosort			246	10.52
478	Robot Deliveries		csfpython	9	16.09
109	Lucky Tickets			251	10.49
146	Color Cubes			214	10.76
323	Next Palindrome		csfpython	104	12.01
366	Image Cutting		oezguery	77	12.52
129	Enumerating Combinations			220	10.71
488	Accurate Curve Fitting		csfpython	2	18.18
468	The Garden of Words		zelevin	14	15.39
151	Word Ladders			201	10.87
164	Page Rank			191	10.96
371	Pages to Print			70	12.69
139	Beam Balance and Masses			202	10.86
208	Neighborhood of a String			162	11.24
437	Elections and Happiness			31	14.07
138	Huffman Coding			198	10.90
360	Whisky Blending		csfpython	73	12.61
253	Beautiful Line Chart			131	11.61
194	Convex Hull and Farmers			163	11.23
433	A Crime on Logic Island		csfpython	31	14.07
201	Point in Polygon			154	11.33
152	RSA Cryptography			178	11.08
137	Shannon-Fano Coding			184	11.02
111	Necklace Count			196	10.91
337	Introducing Zeckendorf		csfpython	79	12.48
192	Gangster Battles			148	11.40
399	Methane Identification		moxieman	45	13.44
110	Lucky Tickets Advanced			186	11.00
199	Employees Web App			142	11.47
244	Introducing SQL			119	11.77
329	Roman Arithmetic		csfpython	76	12.55
269	Fibonacci coding			102	12.04
368	Number Base Palindrome		csfpython	56	13.07
148	Public Key Cryptography Intro			150	11.38
477	Lottery Balls		csfpython	6	16.71
294	Vigenere Cipher			85	12.35
106	Random Search Optimization			166	11.20
486	Two Colour Special Nim		csfpython	2	18.18
124	Knapsack Backtracking			157	11.30
168	Caesar meets BF			138	11.52
245	Aggregations in SQL			105	11.99
202	Dancing Pairs			122	11.73
162	Rubik's Cube			138	11.52
179	Look and Say binary			129	11.64
374	Longest Common Subsequence			48	13.33
214	Sick Travellers			113	11.86
483	Sixes and Sevens		csfpython	3	17.68
102	Travelling Salesman			153	11.34
182	Frodo and Black Riders			121	11.75
475	Medieval Medicine		zelevin	6	16.71
198	Prn Hex Str			113	11.86
459	Number String Multiples of Thirteen		csfpython	12	15.64
177	Nim Game			119	11.77
160	Social Web Scraper			125	11.69
158	Hamming Codes			124	11.70
246	Joins in SQL			91	12.24
466	Dictionary Entries		csfpython	9	16.09
474	Reachable Amounts		gardengnome	6	16.71
185	Simple 3D Scene			112	11.88
463	Crossing Towns		csfpython	10	15.93
359	Find 3 Numbers		csfpython	48	13.33
364	Arthur Engel's Randomizer			46	13.40
449	Space Pirates		csfpython	15	15.27
157	Emirp primE			121	11.75
414	MIDI Variable Length Numbers			27	14.30
258	Text Justification			82	12.41
447	Fixed Product, Minimum Sum		csfpython	15	15.27
372	String Minimization			40	13.64
401	Methane Rotation		moxieman	30	14.13
490	Circuit Board Connections		csfpython	-	20.09
418	Expected Number of Random Moves		moxieman	24	14.50
469	Game of Generals			7	16.48
159	Hard Life			110	11.91
411	Elo Ratings		moxieman	26	14.37
153	Fermat goes hacking RSA			109	11.93
100	Crossing the Road			126	11.68
265	Update in SQL			71	12.66
458	Mountain Panorama		csfpython	10	15.93
384	Equal Hamming Distance		csfpython	33	13.97
115	Gradient Descent for SLE			116	11.82
427	Cheapest Bus Tickets			19	14.89
196	Fibonacci Randomizer			89	12.27
460	Carlsdale Caverns		csfpython	9	16.09
281	Basic Tokenizer			63	12.87
141	Sliding Window Search			105	11.99
291	Squirrels vs. Acorns		zelevin	59	12.98
452	Implication in Logic			11	15.77
277	The Adventure of Morse Code		zelevin	62	12.89
186	Simple 3D Scene (cont)			88	12.29
193	Maximum Flow			85	12.35
166	Page Rank as Eigenvector			92	12.22
210	Ticket Puzzle			79	12.48
142	LZ77 decompression			97	12.13
112	Travelling Salesman Inverted			105	11.99
209	Suffix Array Advanced			78	12.50
464	Graph to Loops Decomposition			7	16.48
434	A Crime on Logic Island Advanced		csfpython	15	15.27
467	Permutation Generator		csfpython	6	16.71
113	Ground Zero			101	12.06
216	Cracking Linear Congruential Generator			73	12.61
203	Tic-Tac-Toe Minimax Algorithm			76	12.55
219	Neural Network Calculation			71	12.66
274	Two Buckets			56	13.07
400	Memory Check			23	14.57
457	Railroad and Hamilton			8	16.27
473	Skittles		csfpython	4	17.30
324	Merge Sort			41	13.60
351	Nicomachus			34	13.92
132	Stream Cipher Breaking			87	12.31
381	Finding Squares		csfpython	26	14.37
107	Knight's Tour			92	12.22
163	Colliding Balls			78	12.50
241	Village Ways			58	13.01
446	Hangman			10	15.93
175	Algae Robot			73	12.61
259	Easter Bunnies		gardengnome	53	13.16
453	SR latch			8	16.27
435	Maze Mapping API-Robot			12	15.64
205	Clustering the Stars			63	12.87
407	River Labyrinth			18	14.98
293	Sums of Triplets			43	13.52
230	Move-To-Front Transform			56	13.07
315	Count the Common Factors		csfpython	37	13.77
403	Hi-Lo dice game			18	14.98
218	Rain Must Fall	DE		57	13.04
335	Venus Visible			32	14.02
445	Formula 1			9	16.09
334	Find all of the SETs		csfpython	32	14.02
406	Wormholes of Cygnus		moxieman	17	15.07
200	Fizz Buzz in Asm			59	12.98
204	Wandering Star			58	13.01
438	Maze Generator			10	15.93
292	Factorial Trailing Zeroes			39	13.68
412	Json Fix			15	15.27
257	Missing Records in SQL			45	13.44
149	Prime Chains			66	12.79
421	Princess and Tiger			13	15.51
390	Card Pairing Solitaire			19	14.89
436	Avoid the Grid Points		csfpython	10	15.93
255	LCM of a range			44	13.48
440	Mud Walker			9	16.09
212	BCD to Hex			52	13.19
423	Russian Dolls		csfpython	12	15.64
233	Language Study			47	13.37
118	Maxit Single-Player			68	12.74
465	Red Blue Hackenbush		csfpython	4	17.30
223	Introducing Scheme			47	13.37
307	The Problem of Too Many Clues		zelevin	32	14.02
147	Color Cubes Advanced			60	12.95
379	Dice with Infinity Sides		telebashna	19	14.89
178	Maze of the Wumpus			54	13.13
180	Simple Game of Sticks			53	13.16
451	Maximize Toy Production		csfpython	6	16.71
247	Towers of Hanoi			40	13.64
439	Power Sum of Digits		csfpython	8	16.27
420	Life on a String		csfpython	11	15.77
426	Weighted Sum of Digits 2		csfpython	10	15.93
229	Burrows-Wheeler Transform			42	13.56
450	Bead Games		csfpython	6	16.71
455	D flip-flop			5	16.98
442	Chomp			7	16.48
352	Hurkle			21	14.72
299	Tree Visualizer			29	14.18
376	Cartesian Tree Visualization			17	15.07
454	Multiplexer 4x4			5	16.98
330	Easter Bunnies Are Back		gardengnome	24	14.50
183	Connect Four			46	13.40
347	Unwanted Multiples		csfpython	21	14.72
338	Throwing Easter Eggs		gardengnome	22	14.64
354	Too Many Divisors		csfpython	19	14.89
284	Rotate Array In-Place			29	14.18
270	Hexlife			31	14.07
409	Election Fever		csfpython	11	15.77
297	Collatz in the Range			27	14.30
388	Fibonacci Guessing Game			14	15.39
479	Robot and the Wall			1	18.89
296	Tree Value	RU	csfpython	27	14.30
405	Three Friendly Knights		csfpython	11	15.77
389	Binary Split Guessing Game		csfpython	13	15.51
290	Every Leaf on Every Tree		zelevin	26	14.37
432	Ball Bearing Collisions		csfpython	7	16.48
470	Shogi Engine			2	18.18
286	Self-Printing Program			26	14.37
238	Bear Hunt			32	14.02
346	Long Decimal Fractions		csfpython	18	14.98
462	Rota Boards		csfpython	3	17.68
392	Fixing an Anagram			12	15.64
353	Hurkle Hunter			17	15.07
243	Grille Encryption			31	14.07
234	Train Merge			32	14.02
375	Space Invaders			14	15.39
312	The Shredder Conundrum		zelevin	22	14.64
256	Rook Jump Maze			29	14.18
357	Ulam's Prime Spiral			16	15.17
349	Burrows		gardengnome	17	15.07
340	Zeckendorf Lite		csfpython	18	14.98
331	Rotating Toy Display		csfpython	19	14.89
339	Parking Lot			18	14.98
217	Personality Swap			33	13.97
298	Revoltle		zelevin	23	14.57
249	Turing Increment			29	14.18
362	Euclid, Manhattan and Chebyshev			15	15.27
287	Palindrome Frog		csfpython	24	14.50
261	Easter Bunnies 2D		gardengnome	27	14.30
300	Run-Length Encoding			22	14.64
417	Unfortunate Bubble Sort		gardengnome	8	16.27
408	Mad Beaver in River Labyrinth			9	16.09
169	Automated Landing			37	13.77
268	Logic Transformation			25	14.43
363	Language Detector			14	15.39
415	Smallest Message		gardengnome	8	16.27
431	King and Rook Checkmate			6	16.71
367	Roguelike 1d			13	15.51
295	Vigenere Cipher Cracker			21	14.72
313	Seven Segment Decoder			19	14.89
285	Rotate Matrix In Place			22	14.64
393	Urban Planning		csfpython	10	15.93
282	Predictable Board Game		csfpython	22	14.64
456	Every Third Bit			3	17.68
271	A Knight some Trolls and a Princess		csfpython	23	14.57
361	Rogue Mazes			13	15.51
275	Three Buckets			22	14.64
398	Collecting Diamonds		csfpython	9	16.09
358	Mandelbrot Set			13	15.51
319	Tower of Hanoi Rules		csfpython	17	15.07
250	Turing Clone			24	14.50
386	Advent Calendar Chocolate		gardengnome	10	15.93
395	Growth of Micro-Organisms		csfpython	9	16.09
424	New Towers of Hanoi		csfpython	6	16.71
344	Throwing Easter Eggs Part 2		gardengnome	14	15.39
443	Football League Tables		csfpython	4	17.30
383	E2C2S - try harder!		gardengnome	10	15.93
382	Die Throw Sequences		csfpython	10	15.93
441	Max versus Min		csfpython	4	17.30
314	The Sorites Solution		zelevin	16	15.17
419	Special Digits		csfpython	6	16.71
341	Zeckendorf Advanced		csfpython	13	15.51
231	Dice Black Jack			23	14.57
416	Socket Server		testuser	6	16.71
260	Low Cost Road Network		csfpython	20	14.80
213	Micro-Life	SK		24	14.50
448	Button Cycles		csfpython	3	17.68
402	Game of Stones		csfpython	7	16.48
220	Neural Network Training			23	14.57
413	Tree Painting		csfpython	6	16.71
332	Easter Bunnies 2D Are Back		gardengnome	13	15.51
387	Big Numbers		csfpython	8	16.27
222	Easter Eggs Advanced			22	14.64
422	Mabinogion Sheep		moxieman	5	16.98
410	Village Door Shuffle		csfpython	6	16.71
289	The Case of the Desperate Mastermind		zelevin	16	15.17
336	Currency Arbitrage			12	15.64
262	Easter Bunnies 2D Advanced		gardengnome	18	14.98
221	XWords		quandray	21	14.72
343	Village of Ticks			11	15.77
254	Rule 30 by Turing			18	14.98
430	Cutting Paper		csfpython	4	17.30
266	Pancake Sorting			17	15.07
404	Methane Normalization		moxieman	6	16.71
391	Scout Proficiency Badges		csfpython	7	16.48
263	Easter Bunnies 3D		gardengnome	17	15.07
288	Langton's Ant		csfpython	15	15.27
326	Sum Them Forth			12	15.64
235	Train Merge Advanced			19	14.89
350	Colourful Egg Sequences		gardengnome	10	15.93
311	The Mirror Maze		zelevin	13	15.51
320	Accordion		pearlbarley	12	15.64
306	Line Drawing Algorithm			13	15.51
279	Two Buckets Advanced		csfpython	15	15.27
305	The Catacombs of Chronos		zelevin	13	15.51
276	Lucky Pairs		csfpython	15	15.27
303	Towers Under Cover			13	15.51
316	Apogee			12	15.64
380	Treap Study			7	16.48
394	Many Shortest Routes		csfpython	6	16.71
309	Board Game Sequences		csfpython	12	15.64
365	Flower Border Arrangements		csfpython	8	16.27
333	Happy Triplets			10	15.93
242	Comment Stripper			16	15.17
345	Elliptic Curves Basics			9	16.09
224	Transposing List of Lists			17	15.07
237	Road Network Destruction			16	15.17
267	Turing Maze			14	15.39
227	Hashtable Implementation			16	15.17
304	Ordered Brackets		csfpython	11	15.77
397	Trading Bot			5	16.98
264	Party Presents		csfpython	13	15.51
378	Space Invaders Automation			6	16.71
327	Dobbin's Long Journey		csfpython	9	16.09
310	Board Game Sequences Advanced		csfpython	10	15.93
342	Adaptive Arithmetic Coding			8	16.27
325	Ultimate Sort Trial			9	16.09
322	Gray Decoder			9	16.09
373	Railroad Rat		csfpython	6	16.71
321	Hanoi Tower Heights		csfpython	9	16.09
225	Hamurabi			14	15.39
328	Beep Beep Beep			8	16.27
308	Circle Drawing Algorithm			9	16.09
252	Shadok and Gibis			12	15.64
283	Predictable Board Game on 10 Boards		csfpython	10	15.93
278	Polyomino Generation			10	15.93
215	Klotski	SK		13	15.51
251	Radio Spies			11	15.77
370	Jewels			5	16.98
369	Flappy Bird			5	16.98
302	Sound-Controlled Robot			8	16.27
280	Three Buckets Re-visited		csfpython	9	16.09
226	Multiplicative Persistence Backtrace			11	15.77
232	Shift Register Randomizer			10	15.93
348	Trick-Taking Game			5	16.98
396	Chocolate Triangles and BF		moxieman	3	17.68
248	Christmas Puzzle			9	16.09
240	Playfair Cipher Cracking			9	16.09
239	Foxes and Geese			9	16.09
236	Is the Earth Flat			9	16.09
273	Logic Glitches			7	16.48
355	Robots Game			4	17.30
272	Hexplore			7	16.48
228	Maze Mapping Robot			8	16.27
356	Robots Game Autoplay			3	17.68
317	Launch to Orbit			4	17.30
318	Launch to Orbit automated			2	18.18