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		59449	1.00
2	Sum in Loop	DE ES FR AR ZH RO RU SK		36042	1.87
3	Sums in Loop	DE ES FR AR ZH RO RU SK		27479	2.34
4	Minimum of Two	DE ES FR AR ZH RO RU SK		23954	2.58
5	Minimum of Three	DE ES FR AR ZH RO RU SK		21452	2.77
15	Maximum of array	DE ES AR ZH RO RU SK		18748	3.00
6	Rounding	DE ES AR ZH RO RU SK		17190	3.16
7	Fahrenheit to Celsius	DE ES AR ZH RO RU SK		16465	3.23
20	Vowel Count	DE ES AR ZH RO RU SK		13371	3.59
11	Sum of digits	DE ES RU ZH SK		13301	3.60
8	Arithmetic Progression	DE ES RU ZH SK		12496	3.71
41	Median of Three	DE ES AR ZH RO RU SK		11447	3.86
9	Triangles	DE ES RU ZH SK		11940	3.79
28	Body Mass Index	DE ES ZH RU SK		11312	3.88
13	Weighted sum of digits	DE ES RU ZH SK		10799	3.96
43	Dice Rolling	DE ES ZH RU SK		9722	4.15
16	Average of an array	DE ES RU SK		10237	4.06
30	Reverse String	DE ES RU SK		9669	4.15
17	Array Checksum	DE ES RU SK		9512	4.18
21	Array Counters	DE ES RU SK		8855	4.31
10	Linear Function	DE ES RU SK		8605	4.36
48	Collatz Sequence	DE ES RU SK		7684	4.55
12	Modulo and time difference	DE ES RU SK		7812	4.53
14	Modular Calculator	ES SK		7226	4.66
27	Bubble Sort	ES RU SK		6552	4.83
26	Greatest Common Divisor	ES SK RU		6377	4.88
18	Square Root	ES RU		6201	4.93
29	Sort with Indexes	RU		5912	5.01
50	Palindromes	DE ES RU SK		5467	5.15
23	Bubble in Array	ES RU		5663	5.08
52	Pythagorean Theorem	RU		5252	5.21
31	Rotate String	ES RU		5428	5.16
67	Fibonacci Sequence	RU		4707	5.41
68	Bicycle Race	ES RU		4675	5.42
24	Neumann's Random Generator	DE ES RU		5065	5.28
57	Smoothing the Weather	ES RU		4664	5.42
35	Savings Calculator			4485	5.49
104	Triangle Area	ES		3747	5.80
25	Linear Congruential Generator	RU		4425	5.51
44	Double Dice Roll	RU		4192	5.61
32	Josephus Problem	RU		4301	5.56
81	Bit Count	RU		3763	5.79
19	Matching Brackets	ES RU		4074	5.66
58	Card Names			3597	5.87
49	Rock Paper Scissors			3651	5.85
47	Caesar Shift Cipher	SK		3653	5.85
128	Combinations Counting			2960	6.21
55	Matching Words			3515	5.91
94	Fool's Day 2014	SK		3069	6.15
59	Bulls and Cows			3177	6.09
61	Prime Numbers Generation	RU		3120	6.12
22	Two Printers	ES RU		3378	5.98
42	Blackjack Counting			2900	6.25
120	Selection Sort			2289	6.66
38	Quadratic Equation			2679	6.38
33	Parity Control	RU		2608	6.43
53	King and Queen			2339	6.62
34	Binary Search			2424	6.56
171	Tree Height Measurement			1630	7.25
37	Mortgage Calculator	ZH		2267	6.67
45	Cards Shuffling	ZH		2215	6.71
69	Fibonacci Divisibility			2056	6.84
63	Integer Factorization	ZH		1981	6.91
46	Tic-Tac-Toe	ZH		2032	6.86
62	Prime Ranges			1809	7.07
72	Funny Words Generator			1752	7.12
121	Insertion Sort			1528	7.36
75	Yacht or Dice Poker			1660	7.22
172	Cloud Altitude Measurement			1232	7.73
39	Share Price Volatility			1691	7.18
127	Anagrams			1361	7.56
134	Flying Text Screensaver			1261	7.69
156	Luhn Algorithm	SK		1108	7.92
114	Tricky Printing			1185	7.80
80	Duel Chances			1262	7.69
36	Code Guesser	UA		1351	7.57
74	Clock Hands			1190	7.79
135	Variable Length Code			993	8.11
54	Pythagorean Triples			1176	7.81
105	Convex Polygon Area			1026	8.05
73	Hexagonal Grid			1060	7.99
145	Modular Exponentiation			866	8.34
97	Girls and Pigs			945	8.19
116	Summing Up			865	8.35
181	Reverse Polish Notation			666	8.80
98	Azimuth at Treasure Island			821	8.44
122	QuickSort			760	8.57
51	Dungeons and Dragons Dice	UA		902	8.27
85	Rotation in 2D Space			826	8.43
40	Paths in the Grid	UA		911	8.26
187	Static Web Page			614	8.94
56	Life is Simple			860	8.36
188	Basics of HTML			585	9.03
66	Caesar Cipher Cracker			785	8.51
70	Most Frequent Word			776	8.53
88	Pitch and Notes			726	8.65
87	Tree Builder			693	8.73
495	Counting Arithmetic Progressions		csfpython	4	17.30
108	Star Medals			640	8.87
60	Sweet Harvest			718	8.67
95	Simple Linear Regression			653	8.83
77	Point to Segment Distance			664	8.81
428	Broken Keyboard			104	12.01
86	Brainfuck Interpreter			604	8.97
211	Information Entropy			418	9.61
71	Fibonacci Divisibility Advanced			622	8.92
91	Game of 2048			581	9.04
207	Suffix Array			407	9.65
101	Gradient Calculation			541	9.16
143	Extended Euclidean Algorithm			476	9.38
480	Coin Payments		csfpython	23	14.58
176	Say 100			425	9.58
82	Levenshtein Distance			549	9.14
191	Spaceship Weight Fraud			393	9.71
119	Brain Fibo			476	9.38
89	Instrument Tuner			513	9.25
206	Base-32 Encoding			364	9.85
494	Holiday Travel		csfpython	4	17.30
154	Breadth First Search			426	9.57
64	Maze Pathfinder			537	9.17
195	Mul Two			371	9.81
79	Cycles Detection			505	9.28
92	Binary Heap			470	9.40
485	Magic 3		csfpython	14	15.39
155	Depth First Search			386	9.75
83	Graph Generator			465	9.42
131	Four Pics One Word			411	9.64
487	Reduce and Equalise		csfpython	11	15.78
301	Skyscraper Price			206	10.83
476	Prime Vowel Count		csfpython	22	14.65
136	Variable Length Code Unpack			371	9.81
90	Lexicographic Permutations			416	9.62
78	Bezier Curves			427	9.57
150	Introducing Regexps			348	9.93
496	Minimum Journey Cost		csfpython	1	18.89
497	Crazy Timer			-	20.10
189	Dynamic Web Page			307	10.14
126	Sequence of Squares			368	9.83
65	Transitive Closure on Candy States			427	9.57
167	Copy Line			314	10.10
385	Number of steps in Euclidean Algorithm		gardengnome	106	11.98
170	Binary Search in Array			306	10.15
99	Uphill Shooting			366	9.84
461	Lucky 7		csfpython	33	13.97
197	Loops in Assembly			269	10.37
117	Divide by Two			339	9.97
161	Topological Sorting			299	10.19
377	Sum of Digits Divisibility			104	12.01
144	Modular Inverse			304	10.16
492	Fastest Clearance		csfpython	4	17.30
429	Moving Average in Time			56	13.07
76	Pawn Move Validator			345	9.94
174	Calculation of Pi			263	10.41
425	Explosive Breeding			58	13.01
93	Starving Priority Queue			323	10.05
133	Billiard Ball			285	10.27
96	Snake Arcade			308	10.14
140	Proper Bracket Sequences			274	10.34
481	Field Trip		csfpython	12	15.64
165	Safe Landing			253	10.48
103	Easter Eggs			285	10.27
184	Matches Picking		quandray	226	10.67
84	Dijkstra in the Network			298	10.19
123	Knapsack of Integers			269	10.37
472	Unreachable Amounts		csfpython	17	15.08
173	Chords of Music			221	10.71
130	Combinations with Repetitions			249	10.50
190	Query String Parameters			208	10.82
109	Lucky Tickets			259	10.44
444	White Rectangle			35	13.87
489	TV Charity Fundraiser		csfpython	5	16.98
125	Bogosort			247	10.52
484	A Message from Deep Space		csfpython	8	16.28
471	Missing Digits		csfpython	16	15.17
366	Image Cutting		oezguery	82	12.42
323	Next Palindrome		csfpython	108	11.95
146	Color Cubes			215	10.76
371	Pages to Print			76	12.55
129	Enumerating Combinations			222	10.70
493	Ternary Logic			2	18.19
437	Elections and Happiness			35	13.87
151	Word Ladders			202	10.87
164	Page Rank			194	10.94
139	Beam Balance and Masses			206	10.83
208	Neighborhood of a String			166	11.21
253	Beautiful Line Chart			140	11.50
360	Whisky Blending		csfpython	77	12.53
138	Huffman Coding			200	10.88
374	Longest Common Subsequence			68	12.74
433	A Crime on Logic Island		csfpython	35	13.87
194	Convex Hull and Farmers			166	11.21
201	Point in Polygon			158	11.29
152	RSA Cryptography			181	11.06
337	Introducing Zeckendorf		csfpython	83	12.40
111	Necklace Count			200	10.88
102	Travelling Salesman			204	10.85
137	Shannon-Fano Coding			185	11.02
482	SS Numbers		csfpython	7	16.48
468	The Garden of Words		zelevin	14	15.39
478	Robot Deliveries		csfpython	9	16.10
399	Methane Identification		moxieman	48	13.34
192	Gangster Battles			150	11.38
110	Lucky Tickets Advanced			190	10.97
244	Introducing SQL			121	11.75
199	Employees Web App			142	11.48
269	Fibonacci coding			107	11.96
329	Roman Arithmetic		csfpython	78	12.51
368	Number Base Palindrome		csfpython	59	12.98
148	Public Key Cryptography Intro			153	11.35
106	Random Search Optimization			170	11.16
124	Knapsack Backtracking			160	11.27
491	Lucky Number Scores		csfpython	2	18.19
245	Aggregations in SQL			107	11.96
294	Vigenere Cipher			86	12.34
168	Caesar meets BF			138	11.52
162	Rubik's Cube			140	11.50
202	Dancing Pairs			123	11.72
214	Sick Travellers			116	11.82
179	Look and Say binary			130	11.63
182	Frodo and Black Riders			123	11.72
414	MIDI Variable Length Numbers			31	14.08
198	Prn Hex Str			113	11.87
490	Circuit Board Connections		csfpython	2	18.19
177	Nim Game			119	11.78
364	Arthur Engel's Randomizer			49	13.30
160	Social Web Scraper			125	11.70
158	Hamming Codes			125	11.70
246	Joins in SQL			92	12.22
449	Space Pirates		csfpython	17	15.08
359	Find 3 Numbers		csfpython	50	13.27
185	Simple 3D Scene			113	11.87
157	Emirp primE			123	11.72
459	Number String Multiples of Thirteen		csfpython	13	15.51
258	Text Justification			85	12.36
466	Dictionary Entries		csfpython	10	15.93
463	Crossing Towns		csfpython	11	15.78
372	String Minimization			42	13.56
401	Methane Rotation		moxieman	32	14.02
418	Expected Number of Random Moves		moxieman	26	14.37
477	Lottery Balls		csfpython	6	16.72
159	Hard Life			111	11.90
100	Crossing the Road			130	11.63
153	Fermat goes hacking RSA			111	11.90
411	Elo Ratings		moxieman	27	14.31
384	Equal Hamming Distance		csfpython	35	13.87
460	Carlsdale Caverns		csfpython	11	15.78
447	Fixed Product, Minimum Sum		csfpython	15	15.28
265	Update in SQL			72	12.64
115	Gradient Descent for SLE			118	11.79
469	Game of Generals			8	16.28
291	Squirrels vs. Acorns		zelevin	63	12.87
281	Basic Tokenizer			66	12.79
324	Merge Sort			52	13.20
475	Medieval Medicine		zelevin	6	16.72
277	The Adventure of Morse Code		zelevin	66	12.79
141	Sliding Window Search			107	11.96
488	Accurate Curve Fitting		csfpython	2	18.19
458	Mountain Panorama		csfpython	11	15.78
196	Fibonacci Randomizer			89	12.28
427	Cheapest Bus Tickets			20	14.81
474	Reachable Amounts		gardengnome	6	16.72
186	Simple 3D Scene (cont)			90	12.26
193	Maximum Flow			86	12.34
112	Travelling Salesman Inverted			109	11.93
210	Ticket Puzzle			81	12.44
166	Page Rank as Eigenvector			93	12.20
452	Implication in Logic			12	15.64
142	LZ77 decompression			99	12.10
209	Suffix Array Advanced			79	12.48
113	Ground Zero			103	12.03
457	Railroad and Hamilton			10	15.93
483	Sixes and Sevens		csfpython	3	17.69
216	Cracking Linear Congruential Generator			74	12.60
434	A Crime on Logic Island Advanced		csfpython	16	15.17
464	Graph to Loops Decomposition			8	16.28
203	Tic-Tac-Toe Minimax Algorithm			77	12.53
219	Neural Network Calculation			72	12.64
274	Two Buckets			57	13.04
467	Permutation Generator		csfpython	7	16.48
351	Nicomachus			36	13.82
486	Two Colour Special Nim		csfpython	2	18.19
107	Knight's Tour			96	12.15
259	Easter Bunnies		gardengnome	58	13.01
400	Memory Check			23	14.58
132	Stream Cipher Breaking			88	12.30
403	Hi-Lo dice game			22	14.65
381	Finding Squares		csfpython	27	14.31
163	Colliding Balls			79	12.48
241	Village Ways			60	12.96
175	Algae Robot			74	12.60
406	Wormholes of Cygnus		moxieman	20	14.81
445	Formula 1			11	15.78
205	Clustering the Stars			65	12.82
335	Venus Visible			35	13.87
230	Move-To-Front Transform			58	13.01
407	River Labyrinth			19	14.89
293	Sums of Triplets			44	13.48
334	Find all of the SETs		csfpython	35	13.87
442	Chomp			11	15.78
315	Count the Common Factors		csfpython	38	13.73
446	Hangman			10	15.93
218	Rain Must Fall	DE		58	13.01
255	LCM of a range			50	13.27
412	Json Fix			17	15.08
292	Factorial Trailing Zeroes			42	13.56
421	Princess and Tiger			15	15.28
204	Wandering Star			60	12.96
435	Maze Mapping API-Robot			12	15.64
200	Fizz Buzz in Asm			59	12.98
473	Skittles		csfpython	4	17.30
453	SR latch			8	16.28
149	Prime Chains			67	12.77
390	Card Pairing Solitaire			20	14.81
436	Avoid the Grid Points		csfpython	11	15.78
212	BCD to Hex			54	13.14
257	Missing Records in SQL			45	13.45
233	Language Study			49	13.30
450	Bead Games		csfpython	8	16.28
423	Russian Dolls		csfpython	13	15.51
118	Maxit Single-Player			69	12.72
438	Maze Generator			10	15.93
307	The Problem of Too Many Clues		zelevin	34	13.92
223	Introducing Scheme			48	13.34
379	Dice with Infinity Sides		telebashna	20	14.81
180	Simple Game of Sticks			55	13.10
247	Towers of Hanoi			43	13.52
147	Color Cubes Advanced			60	12.96
440	Mud Walker			9	16.10
178	Maze of the Wumpus			54	13.14
451	Maximize Toy Production		csfpython	7	16.48
439	Power Sum of Digits		csfpython	9	16.10
229	Burrows-Wheeler Transform			44	13.48
420	Life on a String		csfpython	12	15.64
426	Weighted Sum of Digits 2		csfpython	11	15.78
376	Cartesian Tree Visualization			19	14.89
357	Ulam's Prime Spiral			21	14.73
299	Tree Visualizer			30	14.13
388	Fibonacci Guessing Game			16	15.17
347	Unwanted Multiples		csfpython	22	14.65
465	Red Blue Hackenbush		csfpython	4	17.30
352	Hurkle			21	14.73
338	Throwing Easter Eggs		gardengnome	23	14.58
183	Connect Four			46	13.41
330	Easter Bunnies Are Back		gardengnome	24	14.50
409	Election Fever		csfpython	12	15.64
354	Too Many Divisors		csfpython	20	14.81
270	Hexlife			32	14.02
297	Collatz in the Range			28	14.25
349	Burrows		gardengnome	20	14.81
284	Rotate Array In-Place			29	14.19
405	Three Friendly Knights		csfpython	12	15.64
455	D flip-flop			5	16.98
296	Tree Value	RU	csfpython	27	14.31
389	Binary Split Guessing Game		csfpython	14	15.39
454	Multiplexer 4x4			5	16.98
234	Train Merge			34	13.92
362	Euclid, Manhattan and Chebyshev			17	15.08
256	Rook Jump Maze			31	14.08
392	Fixing an Anagram			13	15.51
286	Self-Printing Program			27	14.31
346	Long Decimal Fractions		csfpython	19	14.89
290	Every Leaf on Every Tree		zelevin	26	14.37
243	Grille Encryption			32	14.02
287	Palindrome Frog		csfpython	26	14.37
238	Bear Hunt			32	14.02
340	Zeckendorf Lite		csfpython	19	14.89
268	Logic Transformation			28	14.25
339	Parking Lot			19	14.89
217	Personality Swap			34	13.92
249	Turing Increment			30	14.13
353	Hurkle Hunter			17	15.08
393	Urban Planning		csfpython	12	15.64
312	The Shredder Conundrum		zelevin	22	14.65
417	Unfortunate Bubble Sort		gardengnome	9	16.10
261	Easter Bunnies 2D		gardengnome	28	14.25
375	Space Invaders			14	15.39
432	Ball Bearing Collisions		csfpython	7	16.48
415	Smallest Message		gardengnome	9	16.10
298	Revoltle		zelevin	23	14.58
331	Rotating Toy Display		csfpython	19	14.89
169	Automated Landing			38	13.73
361	Rogue Mazes			15	15.28
395	Growth of Micro-Organisms		csfpython	11	15.78
300	Run-Length Encoding			22	14.65
367	Roguelike 1d			14	15.39
295	Vigenere Cipher Cracker			22	14.65
382	Die Throw Sequences		csfpython	12	15.64
363	Language Detector			14	15.39
408	Mad Beaver in River Labyrinth			9	16.10
462	Rota Boards		csfpython	3	17.69
398	Collecting Diamonds		csfpython	10	15.93
313	Seven Segment Decoder			19	14.89
285	Rotate Matrix In Place			22	14.65
275	Three Buckets			23	14.58
470	Shogi Engine			2	18.19
282	Predictable Board Game		csfpython	22	14.65
319	Tower of Hanoi Rules		csfpython	18	14.98
271	A Knight some Trolls and a Princess		csfpython	23	14.58
479	Robot and the Wall			1	18.89
250	Turing Clone			25	14.44
431	King and Rook Checkmate			6	16.72
383	E2C2S - try harder!		gardengnome	11	15.78
344	Throwing Easter Eggs Part 2		gardengnome	15	15.28
314	The Sorites Solution		zelevin	18	14.98
419	Special Digits		csfpython	7	16.48
260	Low Cost Road Network		csfpython	23	14.58
358	Mandelbrot Set			13	15.51
448	Button Cycles		csfpython	4	17.30
386	Advent Calendar Chocolate		gardengnome	10	15.93
341	Zeckendorf Advanced		csfpython	14	15.39
456	Every Third Bit			3	17.69
424	New Towers of Hanoi		csfpython	6	16.72
413	Tree Painting		csfpython	7	16.48
402	Game of Stones		csfpython	8	16.28
231	Dice Black Jack			24	14.50
443	Football League Tables		csfpython	4	17.30
220	Neural Network Training			24	14.50
213	Micro-Life	SK		24	14.50
441	Max versus Min		csfpython	4	17.30
222	Easter Eggs Advanced			23	14.58
336	Currency Arbitrage			13	15.51
266	Pancake Sorting			19	14.89
416	Socket Server		testuser	6	16.72
404	Methane Normalization		moxieman	7	16.48
332	Easter Bunnies 2D Are Back		gardengnome	13	15.51
254	Rule 30 by Turing			19	14.89
289	The Case of the Desperate Mastermind		zelevin	16	15.17
387	Big Numbers		csfpython	8	16.28
263	Easter Bunnies 3D		gardengnome	18	14.98
262	Easter Bunnies 2D Advanced		gardengnome	18	14.98
410	Village Door Shuffle		csfpython	6	16.72
221	XWords		quandray	21	14.73
422	Mabinogion Sheep		moxieman	5	16.98
343	Village of Ticks			11	15.78
316	Apogee			13	15.51
380	Treap Study			8	16.28
288	Langton's Ant		csfpython	15	15.28
235	Train Merge Advanced			19	14.89
326	Sum Them Forth			12	15.64
311	The Mirror Maze		zelevin	13	15.51
391	Scout Proficiency Badges		csfpython	7	16.48
350	Colourful Egg Sequences		gardengnome	10	15.93
309	Board Game Sequences		csfpython	13	15.51
430	Cutting Paper		csfpython	4	17.30
279	Two Buckets Advanced		csfpython	15	15.28
320	Accordion		pearlbarley	12	15.64
306	Line Drawing Algorithm			13	15.51
333	Happy Triplets			11	15.78
305	The Catacombs of Chronos		zelevin	13	15.51
304	Ordered Brackets		csfpython	13	15.51
276	Lucky Pairs		csfpython	15	15.28
345	Elliptic Curves Basics			10	15.93
303	Towers Under Cover			13	15.51
342	Adaptive Arithmetic Coding			10	15.93
267	Turing Maze			15	15.28
365	Flower Border Arrangements		csfpython	8	16.28
394	Many Shortest Routes		csfpython	6	16.72
242	Comment Stripper			16	15.17
224	Transposing List of Lists			17	15.08
237	Road Network Destruction			16	15.17
264	Party Presents		csfpython	14	15.39
310	Board Game Sequences Advanced		csfpython	11	15.78
227	Hashtable Implementation			16	15.17
322	Gray Decoder			10	15.93
321	Hanoi Tower Heights		csfpython	10	15.93
369	Flappy Bird			7	16.48
397	Trading Bot			5	16.98
327	Dobbin's Long Journey		csfpython	9	16.10
378	Space Invaders Automation			6	16.72
325	Ultimate Sort Trial			9	16.10
302	Sound-Controlled Robot			10	15.93
373	Railroad Rat		csfpython	6	16.72
283	Predictable Board Game on 10 Boards		csfpython	11	15.78
225	Hamurabi			14	15.39
328	Beep Beep Beep			8	16.28
252	Shadok and Gibis			12	15.64
308	Circle Drawing Algorithm			9	16.10
278	Polyomino Generation			10	15.93
215	Klotski	SK		13	15.51
251	Radio Spies			11	15.78
370	Jewels			5	16.98
280	Three Buckets Re-visited		csfpython	9	16.10
273	Logic Glitches			9	16.10
226	Multiplicative Persistence Backtrace			11	15.78
236	Is the Earth Flat			10	15.93
232	Shift Register Randomizer			10	15.93
348	Trick-Taking Game			5	16.98
248	Christmas Puzzle			9	16.10
396	Chocolate Triangles and BF		moxieman	3	17.69
240	Playfair Cipher Cracking			9	16.10
239	Foxes and Geese			9	16.10
272	Hexplore			7	16.48
355	Robots Game			4	17.30
228	Maze Mapping Robot			8	16.28
356	Robots Game Autoplay			3	17.69
317	Launch to Orbit			4	17.30
318	Launch to Orbit automated			2	18.19