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		59222	1.00
2	Sum in Loop	DE ES FR AR ZH RO RU SK		35882	1.87
3	Sums in Loop	DE ES FR AR ZH RO RU SK		27336	2.34
4	Minimum of Two	DE ES FR AR ZH RO RU SK		23823	2.58
5	Minimum of Three	DE ES FR AR ZH RO RU SK		21320	2.77
15	Maximum of array	DE ES AR ZH RO RU SK		18624	3.01
6	Rounding	DE ES AR ZH RO RU SK		17061	3.16
7	Fahrenheit to Celsius	DE ES AR ZH RO RU SK		16334	3.24
20	Vowel Count	DE ES AR ZH RO RU SK		13239	3.60
11	Sum of digits	DE ES RU ZH SK		13188	3.61
8	Arithmetic Progression	DE ES RU ZH SK		12364	3.72
41	Median of Three	DE ES AR ZH RO RU SK		11325	3.87
9	Triangles	DE ES RU ZH SK		11827	3.80
28	Body Mass Index	DE ES ZH RU SK		11201	3.89
13	Weighted sum of digits	DE ES RU ZH SK		10679	3.98
43	Dice Rolling	DE ES ZH RU SK		9593	4.16
16	Average of an array	DE ES RU SK		10120	4.07
30	Reverse String	DE ES RU SK		9544	4.17
17	Array Checksum	DE ES RU SK		9383	4.20
21	Array Counters	DE ES RU SK		8731	4.33
10	Linear Function	DE ES RU SK		8483	4.38
48	Collatz Sequence	DE ES RU SK		7534	4.58
12	Modulo and time difference	DE ES RU SK		7679	4.55
14	Modular Calculator	ES SK		7116	4.68
27	Bubble Sort	ES RU SK		6414	4.86
26	Greatest Common Divisor	ES SK RU		6237	4.91
18	Square Root	ES RU		6068	4.96
29	Sort with Indexes	RU		5772	5.04
50	Palindromes	DE ES RU SK		5332	5.18
23	Bubble in Array	ES RU		5531	5.12
52	Pythagorean Theorem	RU		5118	5.25
31	Rotate String	ES RU		5282	5.20
67	Fibonacci Sequence	RU		4583	5.44
68	Bicycle Race	ES RU		4546	5.46
24	Neumann's Random Generator	DE ES RU		4928	5.32
57	Smoothing the Weather	ES RU		4549	5.46
35	Savings Calculator			4350	5.54
104	Triangle Area	ES		3644	5.84
25	Linear Congruential Generator	RU		4293	5.56
32	Josephus Problem	RU		4188	5.60
44	Double Dice Roll	RU		4059	5.66
81	Bit Count	RU		3645	5.84
19	Matching Brackets	ES RU		3944	5.71
58	Card Names			3474	5.93
47	Caesar Shift Cipher	SK		3539	5.89
49	Rock Paper Scissors			3516	5.91
128	Combinations Counting			2858	6.27
55	Matching Words			3391	5.97
94	Fool's Day 2014	SK		2978	6.19
59	Bulls and Cows			3085	6.13
61	Prime Numbers Generation	RU		3027	6.17
22	Two Printers	ES RU		3281	6.03
42	Blackjack Counting			2806	6.30
120	Selection Sort			2215	6.71
38	Quadratic Equation			2589	6.44
33	Parity Control	RU		2532	6.48
53	King and Queen			2276	6.66
34	Binary Search			2340	6.61
171	Tree Height Measurement			1581	7.29
37	Mortgage Calculator	ZH		2199	6.72
45	Cards Shuffling	ZH		2141	6.77
69	Fibonacci Divisibility			2006	6.88
63	Integer Factorization	ZH		1928	6.95
46	Tic-Tac-Toe	ZH		1977	6.91
62	Prime Ranges			1760	7.11
72	Funny Words Generator			1713	7.15
121	Insertion Sort			1482	7.41
75	Yacht or Dice Poker			1626	7.24
172	Cloud Altitude Measurement			1200	7.77
127	Anagrams			1349	7.57
39	Share Price Volatility			1639	7.23
134	Flying Text Screensaver			1242	7.71
156	Luhn Algorithm	SK		1087	7.94
114	Tricky Printing			1179	7.80
491	Lucky Number Scores		csfpython	2	18.18
80	Duel Chances			1229	7.73
36	Code Guesser	UA		1298	7.64
74	Clock Hands			1156	7.84
135	Variable Length Code			975	8.13
105	Convex Polygon Area			1007	8.08
54	Pythagorean Triples			1132	7.87
73	Hexagonal Grid			1037	8.03
145	Modular Exponentiation			847	8.38
97	Girls and Pigs			928	8.22
116	Summing Up			858	8.35
181	Reverse Polish Notation			653	8.83
98	Azimuth at Treasure Island			805	8.46
187	Static Web Page			611	8.94
487	Reduce and Equalise		csfpython	9	16.09
485	Magic 3		csfpython	13	15.51
85	Rotation in 2D Space			812	8.45
122	QuickSort			735	8.62
51	Dungeons and Dragons Dice	UA		871	8.33
40	Paths in the Grid	UA		874	8.32
56	Life is Simple			840	8.39
188	Basics of HTML			581	9.03
66	Caesar Cipher Cracker			772	8.54
70	Most Frequent Word			760	8.56
88	Pitch and Notes			712	8.68
480	Coin Payments		csfpython	19	14.89
108	Star Medals			631	8.89
95	Simple Linear Regression			638	8.87
60	Sweet Harvest			694	8.72
87	Tree Builder			648	8.84
77	Point to Segment Distance			651	8.83
86	Brainfuck Interpreter			593	8.99
211	Information Entropy			406	9.65
71	Fibonacci Divisibility Advanced			605	8.96
91	Game of 2048			570	9.06
207	Suffix Array			397	9.69
428	Broken Keyboard			88	12.29
101	Gradient Calculation			527	9.20
176	Say 100			423	9.58
143	Extended Euclidean Algorithm			467	9.41
489	TV Charity Fundraiser		csfpython	3	17.68
82	Levenshtein Distance			537	9.17
191	Spaceship Weight Fraud			383	9.75
119	Brain Fibo			471	9.39
89	Instrument Tuner			500	9.29
195	Mul Two			368	9.82
206	Base-32 Encoding			351	9.90
64	Maze Pathfinder			524	9.21
476	Prime Vowel Count		csfpython	18	14.97
79	Cycles Detection			489	9.33
92	Binary Heap			457	9.45
131	Four Pics One Word			404	9.66
83	Graph Generator			447	9.48
301	Skyscraper Price			196	10.91
136	Variable Length Code Unpack			363	9.85
78	Bezier Curves			418	9.60
90	Lexicographic Permutations			405	9.66
189	Dynamic Web Page			305	10.15
150	Introducing Regexps			343	9.94
126	Sequence of Squares			365	9.84
481	Field Trip		csfpython	10	15.92
65	Transitive Closure on Candy States			415	9.61
167	Copy Line			310	10.12
170	Binary Search in Array			305	10.15
154	Breadth First Search			318	10.07
461	Lucky 7		csfpython	28	14.24
385	Number of steps in Euclidean Algorithm		gardengnome	99	12.09
99	Uphill Shooting			359	9.86
197	Loops in Assembly			269	10.36
117	Divide by Two			335	9.98
144	Modular Inverse			301	10.17
377	Sum of Digits Divisibility			98	12.11
429	Moving Average in Time			52	13.19
174	Calculation of Pi			260	10.42
161	Topological Sorting			270	10.36
155	Depth First Search			271	10.35
76	Pawn Move Validator			334	9.99
482	SS Numbers		csfpython	7	16.48
133	Billiard Ball			281	10.29
425	Explosive Breeding			51	13.23
96	Snake Arcade			303	10.16
165	Safe Landing			250	10.49
140	Proper Bracket Sequences			269	10.36
472	Unreachable Amounts		csfpython	14	15.39
488	Accurate Curve Fitting		csfpython	2	18.18
103	Easter Eggs			281	10.29
93	Starving Priority Queue			288	10.25
184	Matches Picking		quandray	221	10.70
123	Knapsack of Integers			263	10.40
471	Missing Digits		csfpython	14	15.39
478	Robot Deliveries		csfpython	9	16.09
444	White Rectangle			33	13.96
84	Dijkstra in the Network			288	10.25
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
109	Lucky Tickets			248	10.51
484	A Message from Deep Space		csfpython	4	17.29
146	Color Cubes			214	10.76
323	Next Palindrome		csfpython	103	12.02
366	Image Cutting		oezguery	76	12.54
129	Enumerating Combinations			219	10.72
151	Word Ladders			201	10.87
468	The Garden of Words		zelevin	13	15.51
164	Page Rank			190	10.97
371	Pages to Print			68	12.73
139	Beam Balance and Masses			200	10.88
208	Neighborhood of a String			160	11.26
437	Elections and Happiness			30	14.12
138	Huffman Coding			198	10.89
360	Whisky Blending		csfpython	72	12.64
194	Convex Hull and Farmers			162	11.24
201	Point in Polygon			154	11.33
253	Beautiful Line Chart			126	11.67
152	RSA Cryptography			178	11.08
433	A Crime on Logic Island		csfpython	30	14.12
137	Shannon-Fano Coding			184	11.02
111	Necklace Count			196	10.91
337	Introducing Zeckendorf		csfpython	79	12.48
486	Two Colour Special Nim		csfpython	2	18.18
490	Circuit Board Connections		csfpython	-	20.09
399	Methane Identification		moxieman	45	13.44
110	Lucky Tickets Advanced			186	11.00
199	Employees Web App			142	11.47
192	Gangster Battles			145	11.43
244	Introducing SQL			119	11.77
329	Roman Arithmetic		csfpython	76	12.54
477	Lottery Balls		csfpython	6	16.71
269	Fibonacci coding			102	12.04
368	Number Base Palindrome		csfpython	55	13.10
483	Sixes and Sevens		csfpython	3	17.68
148	Public Key Cryptography Intro			148	11.40
106	Random Search Optimization			166	11.20
124	Knapsack Backtracking			157	11.30
294	Vigenere Cipher			84	12.37
245	Aggregations in SQL			105	11.99
168	Caesar meets BF			138	11.52
202	Dancing Pairs			122	11.73
162	Rubik's Cube			137	11.53
179	Look and Say binary			129	11.63
475	Medieval Medicine		zelevin	6	16.71
214	Sick Travellers			113	11.86
374	Longest Common Subsequence			47	13.36
459	Number String Multiples of Thirteen		csfpython	12	15.63
182	Frodo and Black Riders			121	11.74
102	Travelling Salesman			152	11.35
474	Reachable Amounts		gardengnome	6	16.71
198	Prn Hex Str			113	11.86
177	Nim Game			119	11.77
160	Social Web Scraper			125	11.69
463	Crossing Towns		csfpython	10	15.92
158	Hamming Codes			124	11.70
246	Joins in SQL			91	12.23
359	Find 3 Numbers		csfpython	48	13.33
185	Simple 3D Scene			111	11.89
157	Emirp primE			121	11.74
414	MIDI Variable Length Numbers			27	14.30
364	Arthur Engel's Randomizer			44	13.48
258	Text Justification			81	12.43
449	Space Pirates		csfpython	14	15.39
469	Game of Generals			7	16.48
466	Dictionary Entries		csfpython	8	16.27
372	String Minimization			40	13.64
447	Fixed Product, Minimum Sum		csfpython	14	15.39
411	Elo Ratings		moxieman	26	14.36
159	Hard Life			110	11.91
401	Methane Rotation		moxieman	29	14.18
153	Fermat goes hacking RSA			109	11.92
418	Expected Number of Random Moves		moxieman	23	14.57
458	Mountain Panorama		csfpython	10	15.92
100	Crossing the Road			125	11.69
265	Update in SQL			71	12.66
384	Equal Hamming Distance		csfpython	33	13.96
460	Carlsdale Caverns		csfpython	9	16.09
115	Gradient Descent for SLE			116	11.82
427	Cheapest Bus Tickets			19	14.89
196	Fibonacci Randomizer			89	12.27
281	Basic Tokenizer			63	12.87
141	Sliding Window Search			105	11.99
452	Implication in Logic			11	15.77
291	Squirrels vs. Acorns		zelevin	59	12.98
277	The Adventure of Morse Code		zelevin	62	12.89
186	Simple 3D Scene (cont)			88	12.29
193	Maximum Flow			85	12.35
464	Graph to Loops Decomposition			7	16.48
166	Page Rank as Eigenvector			92	12.22
210	Ticket Puzzle			79	12.48
142	LZ77 decompression			97	12.13
467	Permutation Generator		csfpython	6	16.71
209	Suffix Array Advanced			78	12.50
434	A Crime on Logic Island Advanced		csfpython	15	15.27
112	Travelling Salesman Inverted			103	12.02
113	Ground Zero			101	12.06
216	Cracking Linear Congruential Generator			73	12.61
203	Tic-Tac-Toe Minimax Algorithm			76	12.54
219	Neural Network Calculation			71	12.66
473	Skittles		csfpython	4	17.29
274	Two Buckets			56	13.07
400	Memory Check			23	14.57
457	Railroad and Hamilton			8	16.27
324	Merge Sort			41	13.60
351	Nicomachus			34	13.91
132	Stream Cipher Breaking			87	12.31
381	Finding Squares		csfpython	26	14.36
107	Knight's Tour			92	12.22
163	Colliding Balls			78	12.50
446	Hangman			10	15.92
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	15.63
241	Village Ways			56	13.07
407	River Labyrinth			18	14.97
293	Sums of Triplets			43	13.52
205	Clustering the Stars			62	12.89
230	Move-To-Front Transform			56	13.07
445	Formula 1			9	16.09
218	Rain Must Fall	DE		57	13.04
315	Count the Common Factors		csfpython	36	13.82
334	Find all of the SETs		csfpython	32	14.02
200	Fizz Buzz in Asm			59	12.98
204	Wandering Star			58	13.01
335	Venus Visible			31	14.07
438	Maze Generator			10	15.92
403	Hi-Lo dice game			17	15.07
412	Json Fix			15	15.27
406	Wormholes of Cygnus		moxieman	16	15.17
421	Princess and Tiger			13	15.51
436	Avoid the Grid Points		csfpython	10	15.92
257	Missing Records in SQL			45	13.44
149	Prime Chains			66	12.79
292	Factorial Trailing Zeroes			38	13.73
440	Mud Walker			9	16.09
255	LCM of a range			44	13.48
212	BCD to Hex			52	13.19
423	Russian Dolls		csfpython	12	15.63
390	Card Pairing Solitaire			18	14.97
233	Language Study			47	13.36
465	Red Blue Hackenbush		csfpython	4	17.29
118	Maxit Single-Player			68	12.73
223	Introducing Scheme			47	13.36
307	The Problem of Too Many Clues		zelevin	32	14.02
379	Dice with Infinity Sides		telebashna	19	14.89
147	Color Cubes Advanced			60	12.95
178	Maze of the Wumpus			54	13.13
180	Simple Game of Sticks			53	13.16
451	Maximize Toy Production		csfpython	6	16.71
439	Power Sum of Digits		csfpython	8	16.27
247	Towers of Hanoi			40	13.64
426	Weighted Sum of Digits 2		csfpython	10	15.92
420	Life on a String		csfpython	11	15.77
229	Burrows-Wheeler Transform			42	13.56
455	D flip-flop			5	16.98
442	Chomp			7	16.48
454	Multiplexer 4x4			5	16.98
352	Hurkle			21	14.72
299	Tree Visualizer			29	14.18
376	Cartesian Tree Visualization			17	15.07
330	Easter Bunnies Are Back		gardengnome	24	14.50
479	Robot and the Wall			1	18.89
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
409	Election Fever		csfpython	11	15.77
284	Rotate Array In-Place			29	14.18
270	Hexlife			31	14.07
297	Collatz in the Range			27	14.30
296	Tree Value	RU	csfpython	27	14.30
450	Bead Games		csfpython	5	16.98
405	Three Friendly Knights		csfpython	11	15.77
470	Shogi Engine			2	18.18
389	Binary Split Guessing Game		csfpython	13	15.51
388	Fibonacci Guessing Game			13	15.51
290	Every Leaf on Every Tree		zelevin	26	14.36
432	Ball Bearing Collisions		csfpython	7	16.48
462	Rota Boards		csfpython	3	17.68
286	Self-Printing Program			26	14.36
346	Long Decimal Fractions		csfpython	18	14.97
392	Fixing an Anagram			12	15.63
238	Bear Hunt			32	14.02
353	Hurkle Hunter			17	15.07
243	Grille Encryption			31	14.07
375	Space Invaders			14	15.39
234	Train Merge			32	14.02
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	14.97
331	Rotating Toy Display		csfpython	19	14.89
339	Parking Lot			18	14.97
298	Revoltle		zelevin	23	14.57
217	Personality Swap			33	13.96
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
417	Unfortunate Bubble Sort		gardengnome	8	16.27
300	Run-Length Encoding			22	14.64
408	Mad Beaver in River Labyrinth			9	16.09
169	Automated Landing			37	13.77
363	Language Detector			14	15.39
268	Logic Transformation			25	14.43
431	King and Rook Checkmate			6	16.71
367	Roguelike 1d			13	15.51
313	Seven Segment Decoder			19	14.89
295	Vigenere Cipher Cracker			21	14.72
285	Rotate Matrix In Place			22	14.64
456	Every Third Bit			3	17.68
393	Urban Planning		csfpython	10	15.92
282	Predictable Board Game		csfpython	22	14.64
271	A Knight some Trolls and a Princess		csfpython	23	14.57
361	Rogue Mazes			13	15.51
398	Collecting Diamonds		csfpython	9	16.09
275	Three Buckets			22	14.64
358	Mandelbrot Set			13	15.51
319	Tower of Hanoi Rules		csfpython	17	15.07
415	Smallest Message		gardengnome	7	16.48
386	Advent Calendar Chocolate		gardengnome	10	15.92
250	Turing Clone			24	14.50
395	Growth of Micro-Organisms		csfpython	9	16.09
424	New Towers of Hanoi		csfpython	6	16.71
443	Football League Tables		csfpython	4	17.29
344	Throwing Easter Eggs Part 2		gardengnome	14	15.39
383	E2C2S - try harder!		gardengnome	10	15.92
382	Die Throw Sequences		csfpython	10	15.92
441	Max versus Min		csfpython	4	17.29
419	Special Digits		csfpython	6	16.71
314	The Sorites Solution		zelevin	16	15.17
341	Zeckendorf Advanced		csfpython	13	15.51
416	Socket Server		testuser	6	16.71
448	Button Cycles		csfpython	3	17.68
260	Low Cost Road Network		csfpython	20	14.80
213	Micro-Life	SK		24	14.50
402	Game of Stones		csfpython	7	16.48
413	Tree Painting		csfpython	6	16.71
220	Neural Network Training			23	14.57
231	Dice Black Jack			22	14.64
332	Easter Bunnies 2D Are Back		gardengnome	13	15.51
387	Big Numbers		csfpython	8	16.27
422	Mabinogion Sheep		moxieman	5	16.98
410	Village Door Shuffle		csfpython	6	16.71
222	Easter Eggs Advanced			22	14.64
289	The Case of the Desperate Mastermind		zelevin	16	15.17
336	Currency Arbitrage			12	15.63
262	Easter Bunnies 2D Advanced		gardengnome	18	14.97
221	XWords		quandray	21	14.72
430	Cutting Paper		csfpython	4	17.29
343	Village of Ticks			11	15.77
254	Rule 30 by Turing			18	14.97
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	15.63
235	Train Merge Advanced			19	14.89
350	Colourful Egg Sequences		gardengnome	10	15.92
311	The Mirror Maze		zelevin	13	15.51
320	Accordion		pearlbarley	12	15.63
306	Line Drawing Algorithm			13	15.51
279	Two Buckets Advanced		csfpython	15	15.27
305	The Catacombs of Chronos		zelevin	13	15.51
303	Towers Under Cover			13	15.51
276	Lucky Pairs		csfpython	15	15.27
316	Apogee			12	15.63
380	Treap Study			7	16.48
394	Many Shortest Routes		csfpython	6	16.71
309	Board Game Sequences		csfpython	12	15.63
365	Flower Border Arrangements		csfpython	8	16.27
333	Happy Triplets			10	15.92
345	Elliptic Curves Basics			9	16.09
242	Comment Stripper			16	15.17
267	Turing Maze			14	15.39
237	Road Network Destruction			16	15.17
227	Hashtable Implementation			16	15.17
304	Ordered Brackets		csfpython	11	15.77
224	Transposing List of Lists			16	15.17
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	15.92
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	15.63
283	Predictable Board Game on 10 Boards		csfpython	10	15.92
278	Polyomino Generation			10	15.92
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	15.92
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	17.29
272	Hexplore			7	16.48
228	Maze Mapping Robot			8	16.27
356	Robots Game Autoplay			3	17.68
317	Launch to Orbit			4	17.29
318	Launch to Orbit automated			2	18.18