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		59008	1.00
2	Sum in Loop	DE ES FR AR ZH RO RU SK		35753	1.87
3	Sums in Loop	DE ES FR AR ZH RO RU SK		27222	2.34
4	Minimum of Two	DE ES FR AR ZH RO RU SK		23717	2.58
5	Minimum of Three	DE ES FR AR ZH RO RU SK		21224	2.78
15	Maximum of array	DE ES AR ZH RO RU SK		18519	3.01
6	Rounding	DE ES AR ZH RO RU SK		16969	3.16
7	Fahrenheit to Celsius	DE ES AR ZH RO RU SK		16245	3.24
20	Vowel Count	DE ES AR ZH RO RU SK		13162	3.61
11	Sum of digits	DE ES RU ZH SK		13093	3.62
8	Arithmetic Progression	DE ES RU ZH SK		12282	3.73
41	Median of Three	DE ES AR ZH RO RU SK		11265	3.88
9	Triangles	DE ES RU ZH SK		11747	3.80
28	Body Mass Index	DE ES ZH RU SK		11147	3.89
13	Weighted sum of digits	DE ES RU ZH SK		10622	3.98
43	Dice Rolling	DE ES ZH RU SK		9551	4.16
16	Average of an array	DE ES RU SK		10061	4.07
30	Reverse String	DE ES RU SK		9501	4.17
17	Array Checksum	DE ES RU SK		9335	4.20
21	Array Counters	DE ES RU SK		8692	4.33
10	Linear Function	DE ES RU SK		8434	4.38
48	Collatz Sequence	DE ES RU SK		7493	4.58
12	Modulo and time difference	DE ES RU SK		7626	4.55
14	Modular Calculator	ES SK		7037	4.69
27	Bubble Sort	ES RU SK		6369	4.87
26	Greatest Common Divisor	ES SK RU		6197	4.91
18	Square Root	ES RU		6017	4.97
29	Sort with Indexes	RU		5739	5.05
50	Palindromes	DE ES RU SK		5299	5.19
23	Bubble in Array	ES RU		5502	5.12
52	Pythagorean Theorem	RU		5078	5.26
31	Rotate String	ES RU		5257	5.20
67	Fibonacci Sequence	RU		4558	5.45
68	Bicycle Race	ES RU		4519	5.46
24	Neumann's Random Generator	DE ES RU		4908	5.32
57	Smoothing the Weather	ES RU		4532	5.46
35	Savings Calculator			4326	5.54
104	Triangle Area	ES		3613	5.85
25	Linear Congruential Generator	RU		4272	5.56
44	Double Dice Roll	RU		4042	5.66
32	Josephus Problem	RU		4142	5.61
81	Bit Count	RU		3631	5.84
19	Matching Brackets	ES RU		3920	5.71
58	Card Names			3459	5.93
47	Caesar Shift Cipher	SK		3528	5.89
49	Rock Paper Scissors			3502	5.91
128	Combinations Counting			2852	6.26
55	Matching Words			3381	5.97
94	Fool's Day 2014	SK		2959	6.20
59	Bulls and Cows			3075	6.13
61	Prime Numbers Generation	RU		3017	6.16
22	Two Printers	ES RU		3263	6.03
42	Blackjack Counting			2799	6.30
120	Selection Sort			2208	6.71
38	Quadratic Equation			2577	6.44
33	Parity Control	RU		2524	6.47
53	King and Queen			2266	6.66
34	Binary Search			2330	6.61
171	Tree Height Measurement			1574	7.29
37	Mortgage Calculator	ZH		2190	6.72
45	Cards Shuffling	ZH		2135	6.77
69	Fibonacci Divisibility			1998	6.88
63	Integer Factorization	ZH		1917	6.95
46	Tic-Tac-Toe	ZH		1970	6.90
62	Prime Ranges			1753	7.11
72	Funny Words Generator			1704	7.16
121	Insertion Sort			1460	7.43
75	Yacht or Dice Poker			1620	7.24
172	Cloud Altitude Measurement			1192	7.78
127	Anagrams			1341	7.57
39	Share Price Volatility			1630	7.23
487	Reduce and Equalise		csfpython	6	16.70
134	Flying Text Screensaver			1238	7.71
485	Magic 3		csfpython	12	15.63
156	Luhn Algorithm	SK		1077	7.95
114	Tricky Printing			1176	7.80
80	Duel Chances			1224	7.73
36	Code Guesser	UA		1289	7.64
74	Clock Hands			1148	7.84
135	Variable Length Code			969	8.14
105	Convex Polygon Area			1000	8.08
54	Pythagorean Triples			1125	7.88
73	Hexagonal Grid			1030	8.03
145	Modular Exponentiation			842	8.38
97	Girls and Pigs			920	8.23
116	Summing Up			855	8.35
181	Reverse Polish Notation			648	8.83
98	Azimuth at Treasure Island			800	8.47
187	Static Web Page			610	8.94
85	Rotation in 2D Space			808	8.45
122	QuickSort			733	8.62
51	Dungeons and Dragons Dice	UA		865	8.33
40	Paths in the Grid	UA		868	8.33
188	Basics of HTML			581	9.02
56	Life is Simple			833	8.40
480	Coin Payments		csfpython	16	15.16
66	Caesar Cipher Cracker			766	8.54
70	Most Frequent Word			753	8.57
88	Pitch and Notes			705	8.69
108	Star Medals			629	8.89
95	Simple Linear Regression			635	8.87
87	Tree Builder			645	8.84
60	Sweet Harvest			688	8.73
77	Point to Segment Distance			646	8.84
86	Brainfuck Interpreter			590	9.00
476	Prime Vowel Count		csfpython	18	14.97
211	Information Entropy			404	9.65
71	Fibonacci Divisibility Advanced			597	8.98
91	Game of 2048			564	9.08
428	Broken Keyboard			85	12.35
207	Suffix Array			394	9.70
101	Gradient Calculation			526	9.20
143	Extended Euclidean Algorithm			466	9.41
176	Say 100			421	9.58
82	Levenshtein Distance			533	9.17
119	Brain Fibo			471	9.39
191	Spaceship Weight Fraud			378	9.77
195	Mul Two			367	9.82
481	Field Trip		csfpython	9	16.08
89	Instrument Tuner			498	9.29
206	Base-32 Encoding			348	9.91
64	Maze Pathfinder			521	9.21
79	Cycles Detection			484	9.34
92	Binary Heap			455	9.45
131	Four Pics One Word			403	9.66
83	Graph Generator			439	9.51
461	Lucky 7		csfpython	28	14.23
136	Variable Length Code Unpack			362	9.84
301	Skyscraper Price			191	10.95
189	Dynamic Web Page			305	10.14
90	Lexicographic Permutations			404	9.65
78	Bezier Curves			416	9.60
150	Introducing Regexps			342	9.94
126	Sequence of Squares			365	9.83
482	SS Numbers		csfpython	6	16.70
488	Accurate Curve Fitting		csfpython	-	20.08
65	Transitive Closure on Candy States			410	9.63
167	Copy Line			308	10.12
170	Binary Search in Array			304	10.15
154	Breadth First Search			314	10.09
197	Loops in Assembly			268	10.36
99	Uphill Shooting			357	9.87
385	Number of steps in Euclidean Algorithm		gardengnome	94	12.17
478	Robot Deliveries		csfpython	9	16.08
117	Divide by Two			334	9.98
144	Modular Inverse			298	10.18
429	Moving Average in Time			50	13.25
377	Sum of Digits Divisibility			94	12.17
471	Missing Digits		csfpython	14	15.38
472	Unreachable Amounts		csfpython	13	15.50
161	Topological Sorting			269	10.36
174	Calculation of Pi			258	10.43
155	Depth First Search			270	10.35
484	A Message from Deep Space		csfpython	3	17.68
76	Pawn Move Validator			329	10.01
133	Billiard Ball			278	10.30
425	Explosive Breeding			49	13.29
96	Snake Arcade			301	10.16
140	Proper Bracket Sequences			267	10.37
165	Safe Landing			246	10.51
444	White Rectangle			33	13.96
103	Easter Eggs			280	10.29
93	Starving Priority Queue			287	10.25
184	Matches Picking		quandray	220	10.71
123	Knapsack of Integers			261	10.41
84	Dijkstra in the Network			287	10.25
190	Query String Parameters			207	10.81
130	Combinations with Repetitions			247	10.51
173	Chords of Music			211	10.78
125	Bogosort			243	10.53
486	Two Colour Special Nim		csfpython	1	18.88
483	Sixes and Sevens		csfpython	3	17.68
109	Lucky Tickets			247	10.51
323	Next Palindrome		csfpython	102	12.03
468	The Garden of Words		zelevin	12	15.63
146	Color Cubes			211	10.78
366	Image Cutting		oezguery	74	12.58
129	Enumerating Combinations			218	10.72
151	Word Ladders			201	10.86
437	Elections and Happiness			30	14.12
371	Pages to Print			68	12.73
477	Lottery Balls		csfpython	6	16.70
164	Page Rank			187	10.99
208	Neighborhood of a String			159	11.27
139	Beam Balance and Masses			198	10.89
360	Whisky Blending		csfpython	72	12.63
138	Huffman Coding			197	10.90
433	A Crime on Logic Island		csfpython	30	14.12
194	Convex Hull and Farmers			162	11.23
253	Beautiful Line Chart			126	11.67
201	Point in Polygon			152	11.34
152	RSA Cryptography			175	11.10
137	Shannon-Fano Coding			182	11.03
337	Introducing Zeckendorf		csfpython	78	12.49
111	Necklace Count			195	10.91
399	Methane Identification		moxieman	44	13.47
475	Medieval Medicine		zelevin	6	16.70
199	Employees Web App			142	11.46
244	Introducing SQL			119	11.77
192	Gangster Battles			144	11.44
110	Lucky Tickets Advanced			183	11.02
329	Roman Arithmetic		csfpython	75	12.56
474	Reachable Amounts		gardengnome	6	16.70
269	Fibonacci coding			99	12.08
368	Number Base Palindrome		csfpython	52	13.19
294	Vigenere Cipher			84	12.37
245	Aggregations in SQL			105	11.98
148	Public Key Cryptography Intro			147	11.40
459	Number String Multiples of Thirteen		csfpython	12	15.63
124	Knapsack Backtracking			156	11.30
168	Caesar meets BF			137	11.52
106	Random Search Optimization			163	11.22
463	Crossing Towns		csfpython	10	15.92
179	Look and Say binary			129	11.63
162	Rubik's Cube			136	11.54
374	Longest Common Subsequence			47	13.36
202	Dancing Pairs			118	11.78
214	Sick Travellers			112	11.87
469	Game of Generals			7	16.47
182	Frodo and Black Riders			120	11.75
102	Travelling Salesman			151	11.36
198	Prn Hex Str			113	11.86
466	Dictionary Entries		csfpython	8	16.27
177	Nim Game			119	11.77
160	Social Web Scraper			125	11.68
158	Hamming Codes			124	11.70
359	Find 3 Numbers		csfpython	48	13.32
246	Joins in SQL			90	12.25
414	MIDI Variable Length Numbers			27	14.30
185	Simple 3D Scene			111	11.89
157	Emirp primE			120	11.75
447	Fixed Product, Minimum Sum		csfpython	14	15.38
458	Mountain Panorama		csfpython	10	15.92
364	Arthur Engel's Randomizer			43	13.51
372	String Minimization			40	13.63
449	Space Pirates		csfpython	13	15.50
411	Elo Ratings		moxieman	26	14.36
460	Carlsdale Caverns		csfpython	9	16.08
258	Text Justification			78	12.49
401	Methane Rotation		moxieman	29	14.18
418	Expected Number of Random Moves		moxieman	23	14.56
159	Hard Life			110	11.90
153	Fermat goes hacking RSA			108	11.93
452	Implication in Logic			11	15.77
384	Equal Hamming Distance		csfpython	33	13.96
427	Cheapest Bus Tickets			19	14.88
265	Update in SQL			71	12.65
100	Crossing the Road			124	11.70
464	Graph to Loops Decomposition			7	16.47
467	Permutation Generator		csfpython	6	16.70
473	Skittles		csfpython	4	17.29
115	Gradient Descent for SLE			115	11.83
281	Basic Tokenizer			63	12.86
196	Fibonacci Randomizer			89	12.27
291	Squirrels vs. Acorns		zelevin	59	12.97
141	Sliding Window Search			104	12.00
277	The Adventure of Morse Code		zelevin	62	12.89
434	A Crime on Logic Island Advanced		csfpython	15	15.27
193	Maximum Flow			85	12.35
186	Simple 3D Scene (cont)			87	12.31
166	Page Rank as Eigenvector			91	12.23
210	Ticket Puzzle			78	12.49
142	LZ77 decompression			97	12.12
209	Suffix Array Advanced			78	12.49
457	Railroad and Hamilton			8	16.27
112	Travelling Salesman Inverted			101	12.05
400	Memory Check			23	14.56
113	Ground Zero			100	12.07
216	Cracking Linear Congruential Generator			72	12.63
219	Neural Network Calculation			71	12.65
203	Tic-Tac-Toe Minimax Algorithm			75	12.56
446	Hangman			10	15.92
351	Nicomachus			34	13.91
274	Two Buckets			53	13.15
453	SR latch			8	16.27
381	Finding Squares		csfpython	26	14.36
132	Stream Cipher Breaking			87	12.31
107	Knight's Tour			91	12.23
435	Maze Mapping API-Robot			12	15.63
163	Colliding Balls			77	12.52
175	Algae Robot			72	12.63
407	River Labyrinth			18	14.97
259	Easter Bunnies		gardengnome	52	13.19
445	Formula 1			9	16.08
241	Village Ways			55	13.09
205	Clustering the Stars			62	12.89
230	Move-To-Front Transform			56	13.06
293	Sums of Triplets			42	13.55
438	Maze Generator			10	15.92
218	Rain Must Fall	DE		57	13.03
334	Find all of the SETs		csfpython	32	14.01
315	Count the Common Factors		csfpython	36	13.81
403	Hi-Lo dice game			17	15.06
465	Red Blue Hackenbush		csfpython	4	17.29
335	Venus Visible			31	14.06
412	Json Fix			15	15.27
200	Fizz Buzz in Asm			59	12.97
436	Avoid the Grid Points		csfpython	10	15.92
204	Wandering Star			58	13.00
421	Princess and Tiger			13	15.50
406	Wormholes of Cygnus		moxieman	16	15.16
440	Mud Walker			9	16.08
479	Robot and the Wall			1	18.88
257	Missing Records in SQL			45	13.43
292	Factorial Trailing Zeroes			38	13.72
423	Russian Dolls		csfpython	12	15.63
149	Prime Chains			65	12.81
390	Card Pairing Solitaire			18	14.97
212	BCD to Hex			52	13.19
255	LCM of a range			43	13.51
451	Maximize Toy Production		csfpython	6	16.70
233	Language Study			46	13.40
379	Dice with Infinity Sides		telebashna	19	14.88
307	The Problem of Too Many Clues		zelevin	32	14.01
118	Maxit Single-Player			66	12.78
439	Power Sum of Digits		csfpython	8	16.27
147	Color Cubes Advanced			60	12.94
178	Maze of the Wumpus			54	13.12
223	Introducing Scheme			46	13.40
455	D flip-flop			5	16.97
180	Simple Game of Sticks			53	13.15
426	Weighted Sum of Digits 2		csfpython	10	15.92
420	Life on a String		csfpython	11	15.77
454	Multiplexer 4x4			5	16.97
442	Chomp			7	16.47
324	Merge Sort			27	14.30
247	Towers of Hanoi			40	13.63
229	Burrows-Wheeler Transform			41	13.59
352	Hurkle			21	14.71
376	Cartesian Tree Visualization			17	15.06
299	Tree Visualizer			29	14.18
470	Shogi Engine			2	18.18
330	Easter Bunnies Are Back		gardengnome	24	14.49
347	Unwanted Multiples		csfpython	21	14.71
183	Connect Four			46	13.40
338	Throwing Easter Eggs		gardengnome	22	14.64
409	Election Fever		csfpython	11	15.77
354	Too Many Divisors		csfpython	19	14.88
462	Rota Boards		csfpython	3	17.68
284	Rotate Array In-Place			29	14.18
270	Hexlife			31	14.06
297	Collatz in the Range			27	14.30
296	Tree Value	RU	csfpython	27	14.30
405	Three Friendly Knights		csfpython	11	15.77
432	Ball Bearing Collisions		csfpython	7	16.47
389	Binary Split Guessing Game		csfpython	13	15.50
388	Fibonacci Guessing Game			13	15.50
290	Every Leaf on Every Tree		zelevin	26	14.36
392	Fixing an Anagram			12	15.63
286	Self-Printing Program			26	14.36
346	Long Decimal Fractions		csfpython	18	14.97
353	Hurkle Hunter			17	15.06
375	Space Invaders			14	15.38
238	Bear Hunt			32	14.01
243	Grille Encryption			31	14.06
312	The Shredder Conundrum		zelevin	22	14.64
234	Train Merge			32	14.01
357	Ulam's Prime Spiral			16	15.16
256	Rook Jump Maze			29	14.18
349	Burrows		gardengnome	17	15.06
450	Bead Games		csfpython	4	17.29
340	Zeckendorf Lite		csfpython	18	14.97
339	Parking Lot			18	14.97
331	Rotating Toy Display		csfpython	19	14.88
298	Revoltle		zelevin	23	14.56
249	Turing Increment			29	14.18
217	Personality Swap			33	13.96
287	Palindrome Frog		csfpython	24	14.49
408	Mad Beaver in River Labyrinth			9	16.08
261	Easter Bunnies 2D		gardengnome	27	14.30
300	Run-Length Encoding			22	14.64
456	Every Third Bit			3	17.68
431	King and Rook Checkmate			6	16.70
363	Language Detector			14	15.38
169	Automated Landing			37	13.76
362	Euclid, Manhattan and Chebyshev			14	15.38
268	Logic Transformation			25	14.42
393	Urban Planning		csfpython	10	15.92
313	Seven Segment Decoder			19	14.88
295	Vigenere Cipher Cracker			21	14.71
285	Rotate Matrix In Place			22	14.64
282	Predictable Board Game		csfpython	22	14.64
417	Unfortunate Bubble Sort		gardengnome	7	16.47
271	A Knight some Trolls and a Princess		csfpython	23	14.56
398	Collecting Diamonds		csfpython	9	16.08
443	Football League Tables		csfpython	4	17.29
415	Smallest Message		gardengnome	7	16.47
424	New Towers of Hanoi		csfpython	6	16.70
275	Three Buckets			22	14.64
358	Mandelbrot Set			13	15.50
386	Advent Calendar Chocolate		gardengnome	10	15.92
367	Roguelike 1d			12	15.63
395	Growth of Micro-Organisms		csfpython	9	16.08
319	Tower of Hanoi Rules		csfpython	17	15.06
250	Turing Clone			24	14.49
441	Max versus Min		csfpython	4	17.29
383	E2C2S - try harder!		gardengnome	10	15.92
344	Throwing Easter Eggs Part 2		gardengnome	14	15.38
382	Die Throw Sequences		csfpython	10	15.92
361	Rogue Mazes			12	15.63
419	Special Digits		csfpython	6	16.70
448	Button Cycles		csfpython	3	17.68
314	The Sorites Solution		zelevin	16	15.16
416	Socket Server		testuser	6	16.70
341	Zeckendorf Advanced		csfpython	13	15.50
413	Tree Painting		csfpython	6	16.70
402	Game of Stones		csfpython	7	16.47
260	Low Cost Road Network		csfpython	20	14.79
213	Micro-Life	SK		24	14.49
422	Mabinogion Sheep		moxieman	5	16.97
220	Neural Network Training			23	14.56
332	Easter Bunnies 2D Are Back		gardengnome	13	15.50
231	Dice Black Jack			22	14.64
410	Village Door Shuffle		csfpython	6	16.70
387	Big Numbers		csfpython	8	16.27
222	Easter Eggs Advanced			22	14.64
289	The Case of the Desperate Mastermind		zelevin	16	15.16
336	Currency Arbitrage			12	15.63
430	Cutting Paper		csfpython	4	17.29
262	Easter Bunnies 2D Advanced		gardengnome	18	14.97
404	Methane Normalization		moxieman	6	16.70
343	Village of Ticks			11	15.77
221	XWords		quandray	21	14.71
391	Scout Proficiency Badges		csfpython	7	16.47
254	Rule 30 by Turing			18	14.97
266	Pancake Sorting			17	15.06
326	Sum Them Forth			12	15.63
263	Easter Bunnies 3D		gardengnome	17	15.06
288	Langton's Ant		csfpython	15	15.27
350	Colourful Egg Sequences		gardengnome	10	15.92
235	Train Merge Advanced			19	14.88
311	The Mirror Maze		zelevin	13	15.50
320	Accordion		pearlbarley	12	15.63
306	Line Drawing Algorithm			13	15.50
279	Two Buckets Advanced		csfpython	15	15.27
305	The Catacombs of Chronos		zelevin	13	15.50
303	Towers Under Cover			13	15.50
316	Apogee			12	15.63
276	Lucky Pairs		csfpython	15	15.27
394	Many Shortest Routes		csfpython	6	16.70
380	Treap Study			7	16.47
309	Board Game Sequences		csfpython	12	15.63
333	Happy Triplets			10	15.92
345	Elliptic Curves Basics			9	16.08
242	Comment Stripper			16	15.16
267	Turing Maze			14	15.38
237	Road Network Destruction			16	15.16
397	Trading Bot			5	16.97
304	Ordered Brackets		csfpython	11	15.77
365	Flower Border Arrangements		csfpython	7	16.47
378	Space Invaders Automation			6	16.70
264	Party Presents		csfpython	13	15.50
327	Dobbin's Long Journey		csfpython	9	16.08
310	Board Game Sequences Advanced		csfpython	10	15.92
342	Adaptive Arithmetic Coding			8	16.27
227	Hashtable Implementation			15	15.27
325	Ultimate Sort Trial			9	16.08
224	Transposing List of Lists			15	15.27
322	Gray Decoder			9	16.08
321	Hanoi Tower Heights		csfpython	9	16.08
328	Beep Beep Beep			8	16.27
308	Circle Drawing Algorithm			9	16.08
252	Shadok and Gibis			12	15.63
283	Predictable Board Game on 10 Boards		csfpython	10	15.92
225	Hamurabi			13	15.50
278	Polyomino Generation			10	15.92
373	Railroad Rat		csfpython	5	16.97
215	Klotski	SK		13	15.50
251	Radio Spies			11	15.77
370	Jewels			5	16.97
302	Sound-Controlled Robot			8	16.27
280	Three Buckets Re-visited		csfpython	9	16.08
226	Multiplicative Persistence Backtrace			11	15.77
396	Chocolate Triangles and BF		moxieman	3	17.68
232	Shift Register Randomizer			10	15.92
348	Trick-Taking Game			5	16.97
369	Flappy Bird			4	17.29
248	Christmas Puzzle			9	16.08
240	Playfair Cipher Cracking			9	16.08
239	Foxes and Geese			9	16.08
236	Is the Earth Flat			9	16.08
355	Robots Game			4	17.29
273	Logic Glitches			7	16.47
272	Hexplore			7	16.47
228	Maze Mapping Robot			7	16.47
356	Robots Game Autoplay			3	17.68
317	Launch to Orbit			4	17.29
318	Launch to Orbit automated			2	18.18