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		59318	1.00
2	Sum in Loop	DE ES FR AR ZH RO RU SK		35959	1.87
3	Sums in Loop	DE ES FR AR ZH RO RU SK		27403	2.34
4	Minimum of Two	DE ES FR AR ZH RO RU SK		23886	2.58
5	Minimum of Three	DE ES FR AR ZH RO RU SK		21380	2.77
15	Maximum of array	DE ES AR ZH RO RU SK		18686	3.01
6	Rounding	DE ES AR ZH RO RU SK		17120	3.16
7	Fahrenheit to Celsius	DE ES AR ZH RO RU SK		16401	3.23
20	Vowel Count	DE ES AR ZH RO RU SK		13317	3.60
11	Sum of digits	DE ES RU ZH SK		13249	3.60
8	Arithmetic Progression	DE ES RU ZH SK		12438	3.71
41	Median of Three	DE ES AR ZH RO RU SK		11387	3.87
9	Triangles	DE ES RU ZH SK		11888	3.79
28	Body Mass Index	DE ES ZH RU SK		11266	3.89
13	Weighted sum of digits	DE ES RU ZH SK		10746	3.97
43	Dice Rolling	DE ES ZH RU SK		9658	4.15
16	Average of an array	DE ES RU SK		10186	4.06
30	Reverse String	DE ES RU SK		9617	4.16
17	Array Checksum	DE ES RU SK		9460	4.19
21	Array Counters	DE ES RU SK		8805	4.31
10	Linear Function	DE ES RU SK		8555	4.36
48	Collatz Sequence	DE ES RU SK		7617	4.57
12	Modulo and time difference	DE ES RU SK		7764	4.53
14	Modular Calculator	ES SK		7185	4.67
27	Bubble Sort	ES RU SK		6503	4.84
26	Greatest Common Divisor	ES SK RU		6325	4.89
18	Square Root	ES RU		6154	4.94
29	Sort with Indexes	RU		5857	5.02
50	Palindromes	DE ES RU SK		5396	5.16
23	Bubble in Array	ES RU		5612	5.10
52	Pythagorean Theorem	RU		5196	5.23
31	Rotate String	ES RU		5366	5.17
67	Fibonacci Sequence	RU		4658	5.42
68	Bicycle Race	ES RU		4613	5.44
24	Neumann's Random Generator	DE ES RU		5000	5.30
57	Smoothing the Weather	ES RU		4604	5.44
35	Savings Calculator			4415	5.51
104	Triangle Area	ES		3686	5.83
25	Linear Congruential Generator	RU		4361	5.53
32	Josephus Problem	RU		4248	5.58
44	Double Dice Roll	RU		4111	5.64
81	Bit Count	RU		3688	5.83
19	Matching Brackets	ES RU		4007	5.68
58	Card Names			3521	5.91
47	Caesar Shift Cipher	SK		3579	5.88
49	Rock Paper Scissors			3563	5.89
128	Combinations Counting			2894	6.25
55	Matching Words			3436	5.95
94	Fool's Day 2014	SK		3013	6.18
59	Bulls and Cows			3115	6.12
61	Prime Numbers Generation	RU		3054	6.15
22	Two Printers	ES RU		3324	6.01
42	Blackjack Counting			2839	6.28
120	Selection Sort			2250	6.68
38	Quadratic Equation			2630	6.41
33	Parity Control	RU		2564	6.46
53	King and Queen			2301	6.64
34	Binary Search			2384	6.58
171	Tree Height Measurement			1597	7.28
37	Mortgage Calculator	ZH		2225	6.70
45	Cards Shuffling	ZH		2172	6.74
69	Fibonacci Divisibility			2022	6.87
63	Integer Factorization	ZH		1939	6.94
46	Tic-Tac-Toe	ZH		1999	6.89
62	Prime Ranges			1777	7.09
72	Funny Words Generator			1723	7.15
121	Insertion Sort			1498	7.39
75	Yacht or Dice Poker			1634	7.24
172	Cloud Altitude Measurement			1204	7.77
127	Anagrams			1351	7.57
39	Share Price Volatility			1654	7.22
134	Flying Text Screensaver			1246	7.71
156	Luhn Algorithm	SK		1092	7.94
114	Tricky Printing			1180	7.80
80	Duel Chances			1236	7.72
36	Code Guesser	UA		1319	7.61
74	Clock Hands			1162	7.83
135	Variable Length Code			980	8.13
54	Pythagorean Triples			1146	7.85
105	Convex Polygon Area			1013	8.07
73	Hexagonal Grid			1041	8.02
145	Modular Exponentiation			852	8.37
97	Girls and Pigs			931	8.22
116	Summing Up			858	8.36
181	Reverse Polish Notation			657	8.82
98	Azimuth at Treasure Island			808	8.46
494	Holiday Travel		csfpython	1	18.89
122	QuickSort			743	8.61
85	Rotation in 2D Space			814	8.45
187	Static Web Page			611	8.95
51	Dungeons and Dragons Dice	UA		879	8.31
40	Paths in the Grid	UA		889	8.30
56	Life is Simple			846	8.38
188	Basics of HTML			582	9.03
66	Caesar Cipher Cracker			774	8.54
70	Most Frequent Word			762	8.56
88	Pitch and Notes			714	8.68
108	Star Medals			632	8.89
60	Sweet Harvest			700	8.71
95	Simple Linear Regression			642	8.86
87	Tree Builder			651	8.84
77	Point to Segment Distance			652	8.83
86	Brainfuck Interpreter			597	8.99
211	Information Entropy			410	9.64
71	Fibonacci Divisibility Advanced			608	8.95
91	Game of 2048			572	9.06
428	Broken Keyboard			93	12.20
480	Coin Payments		csfpython	20	14.80
485	Magic 3		csfpython	13	15.51
207	Suffix Array			398	9.69
101	Gradient Calculation			531	9.19
143	Extended Euclidean Algorithm			469	9.40
176	Say 100			423	9.58
82	Levenshtein Distance			541	9.16
191	Spaceship Weight Fraud			384	9.75
119	Brain Fibo			472	9.39
487	Reduce and Equalise		csfpython	9	16.09
89	Instrument Tuner			504	9.28
195	Mul Two			368	9.82
206	Base-32 Encoding			354	9.89
64	Maze Pathfinder			528	9.20
79	Cycles Detection			491	9.32
92	Binary Heap			461	9.43
131	Four Pics One Word			405	9.66
476	Prime Vowel Count		csfpython	20	14.80
83	Graph Generator			451	9.47
301	Skyscraper Price			199	10.89
136	Variable Length Code Unpack			367	9.83
78	Bezier Curves			420	9.60
90	Lexicographic Permutations			406	9.65
150	Introducing Regexps			344	9.94
492	Fastest Clearance		csfpython	2	18.18
189	Dynamic Web Page			305	10.15
493	Ternary Logic			1	18.89
126	Sequence of Squares			365	9.84
65	Transitive Closure on Candy States			418	9.60
167	Copy Line			310	10.12
170	Binary Search in Array			305	10.15
385	Number of steps in Euclidean Algorithm		gardengnome	102	12.04
154	Breadth First Search			318	10.08
461	Lucky 7		csfpython	30	14.13
99	Uphill Shooting			359	9.87
197	Loops in Assembly			269	10.37
161	Topological Sorting			297	10.20
117	Divide by Two			335	9.99
144	Modular Inverse			301	10.17
481	Field Trip		csfpython	11	15.78
377	Sum of Digits Divisibility			100	12.08
429	Moving Average in Time			54	13.13
484	A Message from Deep Space		csfpython	8	16.28
174	Calculation of Pi			260	10.43
155	Depth First Search			274	10.34
76	Pawn Move Validator			335	9.99
93	Starving Priority Queue			315	10.09
425	Explosive Breeding			54	13.13
133	Billiard Ball			283	10.28
140	Proper Bracket Sequences			271	10.35
96	Snake Arcade			304	10.16
165	Safe Landing			251	10.49
491	Lucky Number Scores		csfpython	2	18.18
103	Easter Eggs			282	10.29
123	Knapsack of Integers			266	10.39
184	Matches Picking		quandray	222	10.70
471	Missing Digits		csfpython	16	15.17
84	Dijkstra in the Network			289	10.24
472	Unreachable Amounts		csfpython	15	15.28
444	White Rectangle			34	13.92
173	Chords of Music			219	10.72
130	Combinations with Repetitions			248	10.51
190	Query String Parameters			207	10.82
125	Bogosort			246	10.52
489	TV Charity Fundraiser		csfpython	3	17.68
109	Lucky Tickets			254	10.47
323	Next Palindrome		csfpython	105	11.99
146	Color Cubes			214	10.76
482	SS Numbers		csfpython	7	16.48
366	Image Cutting		oezguery	77	12.52
129	Enumerating Combinations			220	10.72
490	Circuit Board Connections		csfpython	2	18.18
371	Pages to Print			72	12.64
478	Robot Deliveries		csfpython	9	16.09
151	Word Ladders			201	10.87
164	Page Rank			191	10.96
139	Beam Balance and Masses			204	10.85
208	Neighborhood of a String			164	11.22
138	Huffman Coding			198	10.90
468	The Garden of Words		zelevin	14	15.39
253	Beautiful Line Chart			133	11.58
437	Elections and Happiness			31	14.07
194	Convex Hull and Farmers			164	11.22
360	Whisky Blending		csfpython	73	12.62
201	Point in Polygon			156	11.31
374	Longest Common Subsequence			63	12.87
152	RSA Cryptography			179	11.07
137	Shannon-Fano Coding			184	11.02
433	A Crime on Logic Island		csfpython	31	14.07
111	Necklace Count			196	10.91
337	Introducing Zeckendorf		csfpython	80	12.46
192	Gangster Battles			148	11.40
399	Methane Identification		moxieman	46	13.40
110	Lucky Tickets Advanced			186	11.01
199	Employees Web App			142	11.47
244	Introducing SQL			120	11.76
102	Travelling Salesman			187	11.00
329	Roman Arithmetic		csfpython	76	12.55
269	Fibonacci coding			103	12.02
368	Number Base Palindrome		csfpython	57	13.04
148	Public Key Cryptography Intro			152	11.35
294	Vigenere Cipher			86	12.33
106	Random Search Optimization			167	11.19
124	Knapsack Backtracking			158	11.29
488	Accurate Curve Fitting		csfpython	2	18.18
245	Aggregations in SQL			106	11.98
168	Caesar meets BF			138	11.52
202	Dancing Pairs			122	11.73
162	Rubik's Cube			138	11.52
214	Sick Travellers			115	11.83
179	Look and Say binary			129	11.64
182	Frodo and Black Riders			122	11.73
477	Lottery Balls		csfpython	6	16.71
198	Prn Hex Str			113	11.87
466	Dictionary Entries		csfpython	10	15.93
177	Nim Game			119	11.78
160	Social Web Scraper			125	11.69
246	Joins in SQL			92	12.22
158	Hamming Codes			124	11.71
185	Simple 3D Scene			112	11.88
459	Number String Multiples of Thirteen		csfpython	12	15.64
157	Emirp primE			121	11.75
359	Find 3 Numbers		csfpython	48	13.33
364	Arthur Engel's Randomizer			46	13.40
414	MIDI Variable Length Numbers			28	14.24
258	Text Justification			82	12.42
475	Medieval Medicine		zelevin	6	16.71
449	Space Pirates		csfpython	15	15.28
463	Crossing Towns		csfpython	10	15.93
486	Two Colour Special Nim		csfpython	2	18.18
474	Reachable Amounts		gardengnome	6	16.71
447	Fixed Product, Minimum Sum		csfpython	15	15.28
372	String Minimization			40	13.64
483	Sixes and Sevens		csfpython	3	17.68
159	Hard Life			110	11.91
401	Methane Rotation		moxieman	30	14.13
418	Expected Number of Random Moves		moxieman	24	14.50
153	Fermat goes hacking RSA			110	11.91
100	Crossing the Road			126	11.68
411	Elo Ratings		moxieman	26	14.37
265	Update in SQL			72	12.64
115	Gradient Descent for SLE			116	11.82
469	Game of Generals			7	16.48
384	Equal Hamming Distance		csfpython	33	13.97
196	Fibonacci Randomizer			89	12.28
141	Sliding Window Search			105	11.99
281	Basic Tokenizer			63	12.87
291	Squirrels vs. Acorns		zelevin	60	12.95
458	Mountain Panorama		csfpython	10	15.93
427	Cheapest Bus Tickets			19	14.89
186	Simple 3D Scene (cont)			89	12.28
277	The Adventure of Morse Code		zelevin	62	12.90
460	Carlsdale Caverns		csfpython	9	16.09
193	Maximum Flow			85	12.35
166	Page Rank as Eigenvector			92	12.22
210	Ticket Puzzle			79	12.48
209	Suffix Array Advanced			79	12.48
112	Travelling Salesman Inverted			106	11.98
452	Implication in Logic			11	15.78
142	LZ77 decompression			97	12.13
113	Ground Zero			101	12.06
216	Cracking Linear Congruential Generator			73	12.62
203	Tic-Tac-Toe Minimax Algorithm			76	12.55
434	A Crime on Logic Island Advanced		csfpython	15	15.28
219	Neural Network Calculation			71	12.66
464	Graph to Loops Decomposition			7	16.48
274	Two Buckets			56	13.07
400	Memory Check			23	14.57
467	Permutation Generator		csfpython	6	16.71
324	Merge Sort			41	13.60
351	Nicomachus			34	13.92
132	Stream Cipher Breaking			87	12.31
107	Knight's Tour			92	12.22
163	Colliding Balls			78	12.50
381	Finding Squares		csfpython	26	14.37
457	Railroad and Hamilton			8	16.28
241	Village Ways			59	12.98
175	Algae Robot			73	12.62
259	Easter Bunnies		gardengnome	53	13.16
473	Skittles		csfpython	4	17.30
446	Hangman			10	15.93
205	Clustering the Stars			63	12.87
445	Formula 1			10	15.93
293	Sums of Triplets			43	13.52
403	Hi-Lo dice game			19	14.89
435	Maze Mapping API-Robot			12	15.64
407	River Labyrinth			18	14.98
230	Move-To-Front Transform			56	13.07
453	SR latch			8	16.28
406	Wormholes of Cygnus		moxieman	18	14.98
335	Venus Visible			33	13.97
315	Count the Common Factors		csfpython	37	13.77
218	Rain Must Fall	DE		57	13.04
334	Find all of the SETs		csfpython	32	14.02
200	Fizz Buzz in Asm			59	12.98
204	Wandering Star			58	13.01
292	Factorial Trailing Zeroes			40	13.64
149	Prime Chains			66	12.79
257	Missing Records in SQL			45	13.44
438	Maze Generator			10	15.93
412	Json Fix			15	15.28
255	LCM of a range			45	13.44
390	Card Pairing Solitaire			19	14.89
421	Princess and Tiger			13	15.51
212	BCD to Hex			52	13.20
436	Avoid the Grid Points		csfpython	10	15.93
233	Language Study			47	13.37
118	Maxit Single-Player			68	12.74
440	Mud Walker			9	16.09
307	The Problem of Too Many Clues		zelevin	33	13.97
423	Russian Dolls		csfpython	12	15.64
450	Bead Games		csfpython	7	16.48
223	Introducing Scheme			47	13.37
147	Color Cubes Advanced			60	12.95
178	Maze of the Wumpus			54	13.13
379	Dice with Infinity Sides		telebashna	19	14.89
180	Simple Game of Sticks			53	13.16
442	Chomp			8	16.28
465	Red Blue Hackenbush		csfpython	4	17.30
247	Towers of Hanoi			40	13.64
229	Burrows-Wheeler Transform			42	13.56
439	Power Sum of Digits		csfpython	8	16.28
420	Life on a String		csfpython	11	15.78
376	Cartesian Tree Visualization			18	14.98
426	Weighted Sum of Digits 2		csfpython	10	15.93
451	Maximize Toy Production		csfpython	6	16.71
352	Hurkle			21	14.72
299	Tree Visualizer			29	14.18
330	Easter Bunnies Are Back		gardengnome	24	14.50
183	Connect Four			46	13.40
455	D flip-flop			5	16.98
347	Unwanted Multiples		csfpython	21	14.72
338	Throwing Easter Eggs		gardengnome	22	14.65
297	Collatz in the Range			28	14.24
454	Multiplexer 4x4			5	16.98
357	Ulam's Prime Spiral			19	14.89
270	Hexlife			31	14.07
284	Rotate Array In-Place			29	14.18
354	Too Many Divisors		csfpython	19	14.89
296	Tree Value	RU	csfpython	27	14.30
388	Fibonacci Guessing Game			14	15.39
409	Election Fever		csfpython	11	15.78
349	Burrows		gardengnome	19	14.89
405	Three Friendly Knights		csfpython	11	15.78
389	Binary Split Guessing Game		csfpython	13	15.51
290	Every Leaf on Every Tree		zelevin	26	14.37
234	Train Merge			33	13.97
286	Self-Printing Program			26	14.37
238	Bear Hunt			32	14.02
346	Long Decimal Fractions		csfpython	18	14.98
243	Grille Encryption			31	14.07
432	Ball Bearing Collisions		csfpython	7	16.48
353	Hurkle Hunter			17	15.07
392	Fixing an Anagram			12	15.64
312	The Shredder Conundrum		zelevin	22	14.65
256	Rook Jump Maze			29	14.18
479	Robot and the Wall			1	18.89
375	Space Invaders			14	15.39
340	Zeckendorf Lite		csfpython	18	14.98
217	Personality Swap			33	13.97
331	Rotating Toy Display		csfpython	19	14.89
249	Turing Increment			29	14.18
298	Revoltle		zelevin	23	14.57
339	Parking Lot			18	14.98
462	Rota Boards		csfpython	3	17.68
362	Euclid, Manhattan and Chebyshev			15	15.28
287	Palindrome Frog		csfpython	24	14.50
470	Shogi Engine			2	18.18
261	Easter Bunnies 2D		gardengnome	27	14.30
300	Run-Length Encoding			22	14.65
169	Automated Landing			37	13.77
417	Unfortunate Bubble Sort		gardengnome	8	16.28
408	Mad Beaver in River Labyrinth			9	16.09
268	Logic Transformation			25	14.43
363	Language Detector			14	15.39
415	Smallest Message		gardengnome	8	16.28
295	Vigenere Cipher Cracker			21	14.72
395	Growth of Micro-Organisms		csfpython	10	15.93
313	Seven Segment Decoder			19	14.89
285	Rotate Matrix In Place			22	14.65
431	King and Rook Checkmate			6	16.71
367	Roguelike 1d			13	15.51
282	Predictable Board Game		csfpython	22	14.65
319	Tower of Hanoi Rules		csfpython	18	14.98
393	Urban Planning		csfpython	10	15.93
271	A Knight some Trolls and a Princess		csfpython	23	14.57
314	The Sorites Solution		zelevin	18	14.98
275	Three Buckets			22	14.65
361	Rogue Mazes			13	15.51
398	Collecting Diamonds		csfpython	9	16.09
456	Every Third Bit			3	17.68
358	Mandelbrot Set			13	15.51
250	Turing Clone			24	14.50
386	Advent Calendar Chocolate		gardengnome	10	15.93
344	Throwing Easter Eggs Part 2		gardengnome	14	15.39
424	New Towers of Hanoi		csfpython	6	16.71
383	E2C2S - try harder!		gardengnome	10	15.93
382	Die Throw Sequences		csfpython	10	15.93
443	Football League Tables		csfpython	4	17.30
441	Max versus Min		csfpython	4	17.30
419	Special Digits		csfpython	6	16.71
341	Zeckendorf Advanced		csfpython	13	15.51
231	Dice Black Jack			23	14.57
260	Low Cost Road Network		csfpython	20	14.80
213	Micro-Life	SK		24	14.50
416	Socket Server		testuser	6	16.71
220	Neural Network Training			23	14.57
402	Game of Stones		csfpython	7	16.48
332	Easter Bunnies 2D Are Back		gardengnome	13	15.51
413	Tree Painting		csfpython	6	16.71
448	Button Cycles		csfpython	3	17.68
222	Easter Eggs Advanced			22	14.65
387	Big Numbers		csfpython	8	16.28
266	Pancake Sorting			18	14.98
289	The Case of the Desperate Mastermind		zelevin	16	15.17
410	Village Door Shuffle		csfpython	6	16.71
422	Mabinogion Sheep		moxieman	5	16.98
263	Easter Bunnies 3D		gardengnome	18	14.98
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	15.78
254	Rule 30 by Turing			18	14.98
288	Langton's Ant		csfpython	15	15.28
235	Train Merge Advanced			19	14.89
404	Methane Normalization		moxieman	6	16.71
391	Scout Proficiency Badges		csfpython	7	16.48
326	Sum Them Forth			12	15.64
430	Cutting Paper		csfpython	4	17.30
311	The Mirror Maze		zelevin	13	15.51
350	Colourful Egg Sequences		gardengnome	10	15.93
320	Accordion		pearlbarley	12	15.64
306	Line Drawing Algorithm			13	15.51
279	Two Buckets Advanced		csfpython	15	15.28
305	The Catacombs of Chronos		zelevin	13	15.51
276	Lucky Pairs		csfpython	15	15.28
303	Towers Under Cover			13	15.51
316	Apogee			12	15.64
309	Board Game Sequences		csfpython	12	15.64
380	Treap Study			7	16.48
394	Many Shortest Routes		csfpython	6	16.71
365	Flower Border Arrangements		csfpython	8	16.28
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
264	Party Presents		csfpython	14	15.39
227	Hashtable Implementation			16	15.17
304	Ordered Brackets		csfpython	11	15.78
397	Trading Bot			5	16.98
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	16.28
325	Ultimate Sort Trial			9	16.09
322	Gray Decoder			9	16.09
321	Hanoi Tower Heights		csfpython	9	16.09
373	Railroad Rat		csfpython	6	16.71
225	Hamurabi			14	15.39
328	Beep Beep Beep			8	16.28
252	Shadok and Gibis			12	15.64
308	Circle Drawing Algorithm			9	16.09
283	Predictable Board Game on 10 Boards		csfpython	10	15.93
302	Sound-Controlled Robot			9	16.09
278	Polyomino Generation			10	15.93
215	Klotski	SK		13	15.51
251	Radio Spies			11	15.78
370	Jewels			5	16.98
369	Flappy Bird			5	16.98
280	Three Buckets Re-visited		csfpython	9	16.09
226	Multiplicative Persistence Backtrace			11	15.78
232	Shift Register Randomizer			10	15.93
348	Trick-Taking Game			5	16.98
273	Logic Glitches			8	16.28
248	Christmas Puzzle			9	16.09
396	Chocolate Triangles and BF		moxieman	3	17.68
240	Playfair Cipher Cracking			9	16.09
239	Foxes and Geese			9	16.09
236	Is the Earth Flat			9	16.09
272	Hexplore			7	16.48
355	Robots Game			4	17.30
228	Maze Mapping Robot			8	16.28
356	Robots Game Autoplay			3	17.68
317	Launch to Orbit			4	17.30
318	Launch to Orbit automated			2	18.18