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		59547	1.00
2	Sum in Loop	DE ES FR AR ZH RO RU SK		36087	1.87
3	Sums in Loop	DE ES FR AR ZH RO RU SK		27518	2.34
4	Minimum of Two	DE ES FR AR ZH RO RU SK		23992	2.58
5	Minimum of Three	DE ES FR AR ZH RO RU SK		21480	2.77
15	Maximum of array	DE ES AR ZH RO RU SK		18777	3.00
6	Rounding	DE ES AR ZH RO RU SK		17217	3.16
7	Fahrenheit to Celsius	DE ES AR ZH RO RU SK		16489	3.23
20	Vowel Count	DE ES AR ZH RO RU SK		13395	3.59
11	Sum of digits	DE ES RU ZH SK		13326	3.60
8	Arithmetic Progression	DE ES RU ZH SK		12518	3.71
41	Median of Three	DE ES AR ZH RO RU SK		11463	3.86
9	Triangles	DE ES RU ZH SK		11961	3.79
28	Body Mass Index	DE ES ZH RU SK		11331	3.88
13	Weighted sum of digits	DE ES RU ZH SK		10819	3.96
43	Dice Rolling	DE ES ZH RU SK		9739	4.15
16	Average of an array	DE ES RU SK		10258	4.06
30	Reverse String	DE ES RU SK		9690	4.15
17	Array Checksum	DE ES RU SK		9535	4.18
21	Array Counters	DE ES RU SK		8877	4.31
10	Linear Function	DE ES RU SK		8627	4.36
48	Collatz Sequence	DE ES RU SK		7705	4.55
12	Modulo and time difference	DE ES RU SK		7834	4.52
14	Modular Calculator	ES SK		7246	4.66
27	Bubble Sort	ES RU SK		6572	4.83
26	Greatest Common Divisor	ES SK RU		6398	4.88
18	Square Root	ES RU		6221	4.92
29	Sort with Indexes	RU		5929	5.01
50	Palindromes	DE ES RU SK		5487	5.14
23	Bubble in Array	ES RU		5685	5.08
52	Pythagorean Theorem	RU		5266	5.21
31	Rotate String	ES RU		5445	5.16
67	Fibonacci Sequence	RU		4727	5.40
68	Bicycle Race	ES RU		4700	5.41
24	Neumann's Random Generator	DE ES RU		5091	5.27
57	Smoothing the Weather	ES RU		4692	5.41
35	Savings Calculator			4504	5.48
104	Triangle Area	ES		3770	5.79
25	Linear Congruential Generator	RU		4452	5.50
44	Double Dice Roll	RU		4219	5.60
32	Josephus Problem	RU		4322	5.56
81	Bit Count	RU		3788	5.79
19	Matching Brackets	ES RU		4100	5.65
58	Card Names			3623	5.86
49	Rock Paper Scissors			3680	5.84
47	Caesar Shift Cipher	SK		3688	5.83
128	Combinations Counting			2988	6.20
55	Matching Words			3541	5.90
94	Fool's Day 2014	SK		3096	6.14
59	Bulls and Cows			3219	6.07
61	Prime Numbers Generation	RU		3160	6.10
22	Two Printers	ES RU		3421	5.96
42	Blackjack Counting			2943	6.22
120	Selection Sort			2322	6.64
38	Quadratic Equation			2723	6.36
33	Parity Control	RU		2653	6.40
53	King and Queen			2378	6.59
34	Binary Search			2463	6.53
171	Tree Height Measurement			1664	7.21
37	Mortgage Calculator	ZH		2309	6.65
45	Cards Shuffling	ZH		2249	6.69
69	Fibonacci Divisibility			2095	6.81
63	Integer Factorization	ZH		2017	6.88
46	Tic-Tac-Toe	ZH		2071	6.83
62	Prime Ranges			1847	7.03
72	Funny Words Generator			1790	7.09
121	Insertion Sort			1552	7.33
75	Yacht or Dice Poker			1690	7.19
172	Cloud Altitude Measurement			1263	7.69
39	Share Price Volatility			1731	7.15
127	Anagrams			1367	7.56
134	Flying Text Screensaver			1282	7.67
156	Luhn Algorithm	SK		1132	7.88
80	Duel Chances			1298	7.65
114	Tricky Printing			1192	7.79
36	Code Guesser	UA		1388	7.53
74	Clock Hands			1222	7.75
135	Variable Length Code			1011	8.08
54	Pythagorean Triples			1208	7.77
105	Convex Polygon Area			1050	8.01
73	Hexagonal Grid			1085	7.96
145	Modular Exponentiation			889	8.30
97	Girls and Pigs			965	8.16
116	Summing Up			869	8.34
181	Reverse Polish Notation			681	8.76
98	Azimuth at Treasure Island			839	8.40
122	QuickSort			778	8.53
51	Dungeons and Dragons Dice	UA		920	8.24
40	Paths in the Grid	UA		931	8.22
85	Rotation in 2D Space			839	8.40
501	Moving Stones		csfpython	1	18.90
56	Life is Simple			876	8.33
187	Static Web Page			615	8.94
188	Basics of HTML			586	9.02
66	Caesar Cipher Cracker			800	8.48
70	Most Frequent Word			792	8.50
88	Pitch and Notes			742	8.62
87	Tree Builder			709	8.69
60	Sweet Harvest			735	8.63
108	Star Medals			655	8.83
95	Simple Linear Regression			665	8.81
77	Point to Segment Distance			674	8.78
428	Broken Keyboard			113	11.87
86	Brainfuck Interpreter			614	8.94
71	Fibonacci Divisibility Advanced			635	8.89
211	Information Entropy			424	9.59
91	Game of 2048			594	9.00
495	Counting Arithmetic Progressions		csfpython	9	16.10
207	Suffix Array			417	9.61
101	Gradient Calculation			547	9.14
143	Extended Euclidean Algorithm			481	9.37
82	Levenshtein Distance			559	9.11
176	Say 100			426	9.58
191	Spaceship Weight Fraud			402	9.68
154	Breadth First Search			439	9.53
89	Instrument Tuner			520	9.23
206	Base-32 Encoding			371	9.82
119	Brain Fibo			476	9.39
64	Maze Pathfinder			543	9.16
79	Cycles Detection			517	9.24
195	Mul Two			373	9.81
92	Binary Heap			476	9.39
83	Graph Generator			476	9.39
480	Coin Payments		csfpython	24	14.51
155	Depth First Search			393	9.72
131	Four Pics One Word			413	9.63
301	Skyscraper Price			216	10.75
136	Variable Length Code Unpack			375	9.80
90	Lexicographic Permutations			422	9.59
78	Bezier Curves			434	9.55
150	Introducing Regexps			351	9.91
500	Enchanted Necklace		csfpython	1	18.90
499	Binary Frog		csfpython	2	18.19
485	Magic 3		csfpython	16	15.18
65	Transitive Closure on Candy States			435	9.54
126	Sequence of Squares			371	9.82
189	Dynamic Web Page			308	10.14
385	Number of steps in Euclidean Algorithm		gardengnome	112	11.89
167	Copy Line			317	10.09
170	Binary Search in Array			309	10.13
99	Uphill Shooting			369	9.83
161	Topological Sorting			311	10.12
197	Loops in Assembly			272	10.35
117	Divide by Two			342	9.96
377	Sum of Digits Divisibility			110	11.92
476	Prime Vowel Count		csfpython	22	14.65
144	Modular Inverse			312	10.12
461	Lucky 7		csfpython	33	13.97
76	Pawn Move Validator			350	9.92
429	Moving Average in Time			59	12.99
174	Calculation of Pi			268	10.38
425	Explosive Breeding			62	12.90
93	Starving Priority Queue			328	10.03
487	Reduce and Equalise		csfpython	11	15.78
133	Billiard Ball			291	10.24
96	Snake Arcade			313	10.11
140	Proper Bracket Sequences			278	10.32
165	Safe Landing			255	10.47
494	Holiday Travel		csfpython	5	16.99
498	Sum of Divisors Chaining			2	18.19
184	Matches Picking		quandray	236	10.60
103	Easter Eggs			293	10.23
84	Dijkstra in the Network			304	10.16
123	Knapsack of Integers			274	10.34
173	Chords of Music			227	10.67
109	Lucky Tickets			271	10.36
130	Combinations with Repetitions			255	10.47
125	Bogosort			254	10.47
190	Query String Parameters			209	10.81
366	Image Cutting		oezguery	89	12.28
444	White Rectangle			37	13.78
323	Next Palindrome		csfpython	115	11.84
472	Unreachable Amounts		csfpython	18	14.98
371	Pages to Print			81	12.44
146	Color Cubes			221	10.71
481	Field Trip		csfpython	12	15.64
129	Enumerating Combinations			226	10.68
492	Fastest Clearance		csfpython	5	16.99
437	Elections and Happiness			38	13.74
151	Word Ladders			204	10.85
471	Missing Digits		csfpython	17	15.08
164	Page Rank			195	10.93
253	Beautiful Line Chart			143	11.47
139	Beam Balance and Masses			208	10.82
208	Neighborhood of a String			168	11.19
433	A Crime on Logic Island		csfpython	38	13.74
360	Whisky Blending		csfpython	79	12.49
374	Longest Common Subsequence			71	12.67
138	Huffman Coding			202	10.87
484	A Message from Deep Space		csfpython	9	16.10
194	Convex Hull and Farmers			168	11.19
201	Point in Polygon			162	11.25
489	TV Charity Fundraiser		csfpython	6	16.72
337	Introducing Zeckendorf		csfpython	87	12.32
152	RSA Cryptography			185	11.02
111	Necklace Count			204	10.85
137	Shannon-Fano Coding			187	11.00
102	Travelling Salesman			205	10.84
110	Lucky Tickets Advanced			195	10.93
496	Minimum Journey Cost		csfpython	2	18.19
192	Gangster Battles			152	11.36
269	Fibonacci coding			113	11.87
244	Introducing SQL			122	11.74
399	Methane Identification		moxieman	48	13.34
199	Employees Web App			142	11.48
329	Roman Arithmetic		csfpython	80	12.47
368	Number Base Palindrome		csfpython	61	12.93
148	Public Key Cryptography Intro			157	11.30
493	Ternary Logic			3	17.69
468	The Garden of Words		zelevin	14	15.40
106	Random Search Optimization			173	11.14
124	Knapsack Backtracking			164	11.23
294	Vigenere Cipher			89	12.28
162	Rubik's Cube			143	11.47
245	Aggregations in SQL			107	11.97
202	Dancing Pairs			125	11.70
478	Robot Deliveries		csfpython	9	16.10
168	Caesar meets BF			138	11.53
214	Sick Travellers			116	11.83
179	Look and Say binary			130	11.63
482	SS Numbers		csfpython	7	16.49
497	Crazy Timer			1	18.90
449	Space Pirates		csfpython	20	14.81
182	Frodo and Black Riders			125	11.70
414	MIDI Variable Length Numbers			33	13.97
364	Arthur Engel's Randomizer			51	13.24
198	Prn Hex Str			113	11.87
177	Nim Game			119	11.78
258	Text Justification			89	12.28
160	Social Web Scraper			125	11.70
246	Joins in SQL			93	12.21
158	Hamming Codes			125	11.70
359	Find 3 Numbers		csfpython	51	13.24
185	Simple 3D Scene			113	11.87
157	Emirp primE			123	11.73
418	Expected Number of Random Moves		moxieman	28	14.25
372	String Minimization			43	13.53
490	Circuit Board Connections		csfpython	3	17.69
100	Crossing the Road			131	11.62
401	Methane Rotation		moxieman	32	14.03
153	Fermat goes hacking RSA			113	11.87
159	Hard Life			111	11.90
459	Number String Multiples of Thirteen		csfpython	13	15.51
281	Basic Tokenizer			69	12.72
384	Equal Hamming Distance		csfpython	36	13.83
291	Squirrels vs. Acorns		zelevin	65	12.82
115	Gradient Descent for SLE			119	11.78
265	Update in SQL			72	12.65
411	Elo Ratings		moxieman	27	14.31
463	Crossing Towns		csfpython	11	15.78
277	The Adventure of Morse Code		zelevin	68	12.74
466	Dictionary Entries		csfpython	10	15.93
324	Merge Sort			53	13.17
141	Sliding Window Search			107	11.97
112	Travelling Salesman Inverted			115	11.84
196	Fibonacci Randomizer			89	12.28
186	Simple 3D Scene (cont)			91	12.24
447	Fixed Product, Minimum Sum		csfpython	15	15.28
488	Accurate Curve Fitting		csfpython	3	17.69
460	Carlsdale Caverns		csfpython	11	15.78
193	Maximum Flow			87	12.32
166	Page Rank as Eigenvector			94	12.19
210	Ticket Puzzle			81	12.44
142	LZ77 decompression			100	12.08
427	Cheapest Bus Tickets			20	14.81
477	Lottery Balls		csfpython	6	16.72
209	Suffix Array Advanced			79	12.49
458	Mountain Panorama		csfpython	11	15.78
469	Game of Generals			8	16.28
491	Lucky Number Scores		csfpython	2	18.19
113	Ground Zero			104	12.01
274	Two Buckets			60	12.96
434	A Crime on Logic Island Advanced		csfpython	17	15.08
203	Tic-Tac-Toe Minimax Algorithm			78	12.51
216	Cracking Linear Congruential Generator			74	12.60
452	Implication in Logic			12	15.64
475	Medieval Medicine		zelevin	6	16.72
219	Neural Network Calculation			72	12.65
107	Knight's Tour			99	12.10
259	Easter Bunnies		gardengnome	60	12.96
474	Reachable Amounts		gardengnome	6	16.72
381	Finding Squares		csfpython	29	14.19
351	Nicomachus			36	13.83
457	Railroad and Hamilton			10	15.93
132	Stream Cipher Breaking			89	12.28
403	Hi-Lo dice game			23	14.58
241	Village Ways			61	12.93
464	Graph to Loops Decomposition			8	16.28
163	Colliding Balls			79	12.49
400	Memory Check			23	14.58
293	Sums of Triplets			47	13.37
175	Algae Robot			74	12.60
467	Permutation Generator		csfpython	7	16.49
205	Clustering the Stars			65	12.82
406	Wormholes of Cygnus		moxieman	20	14.81
230	Move-To-Front Transform			58	13.02
335	Venus Visible			35	13.87
334	Find all of the SETs		csfpython	35	13.87
412	Json Fix			18	14.98
407	River Labyrinth			19	14.90
445	Formula 1			11	15.78
483	Sixes and Sevens		csfpython	3	17.69
315	Count the Common Factors		csfpython	38	13.74
218	Rain Must Fall	DE		58	13.02
255	LCM of a range			50	13.27
390	Card Pairing Solitaire			22	14.65
292	Factorial Trailing Zeroes			42	13.57
204	Wandering Star			60	12.96
442	Chomp			11	15.78
200	Fizz Buzz in Asm			59	12.99
421	Princess and Tiger			15	15.28
446	Hangman			10	15.93
435	Maze Mapping API-Robot			12	15.64
149	Prime Chains			67	12.77
212	BCD to Hex			54	13.14
257	Missing Records in SQL			45	13.45
118	Maxit Single-Player			71	12.67
486	Two Colour Special Nim		csfpython	2	18.19
233	Language Study			49	13.30
307	The Problem of Too Many Clues		zelevin	35	13.87
388	Fibonacci Guessing Game			20	14.81
453	SR latch			8	16.28
436	Avoid the Grid Points		csfpython	11	15.78
223	Introducing Scheme			49	13.30
379	Dice with Infinity Sides		telebashna	21	14.73
423	Russian Dolls		csfpython	13	15.51
180	Simple Game of Sticks			56	13.08
450	Bead Games		csfpython	8	16.28
247	Towers of Hanoi			43	13.53
473	Skittles		csfpython	4	17.30
438	Maze Generator			10	15.93
147	Color Cubes Advanced			60	12.96
420	Life on a String		csfpython	13	15.51
178	Maze of the Wumpus			54	13.14
376	Cartesian Tree Visualization			20	14.81
229	Burrows-Wheeler Transform			44	13.49
440	Mud Walker			9	16.10
439	Power Sum of Digits		csfpython	9	16.10
426	Weighted Sum of Digits 2		csfpython	11	15.78
451	Maximize Toy Production		csfpython	7	16.49
299	Tree Visualizer			30	14.13
357	Ulam's Prime Spiral			21	14.73
389	Binary Split Guessing Game		csfpython	16	15.18
347	Unwanted Multiples		csfpython	22	14.65
183	Connect Four			46	13.41
352	Hurkle			21	14.73
270	Hexlife			33	13.97
338	Throwing Easter Eggs		gardengnome	23	14.58
330	Easter Bunnies Are Back		gardengnome	24	14.51
354	Too Many Divisors		csfpython	20	14.81
297	Collatz in the Range			28	14.25
409	Election Fever		csfpython	12	15.64
284	Rotate Array In-Place			29	14.19
349	Burrows		gardengnome	20	14.81
392	Fixing an Anagram			14	15.40
296	Tree Value	RU	csfpython	27	14.31
362	Euclid, Manhattan and Chebyshev			18	14.98
465	Red Blue Hackenbush		csfpython	4	17.30
234	Train Merge			35	13.87
405	Three Friendly Knights		csfpython	12	15.64
256	Rook Jump Maze			31	14.08
286	Self-Printing Program			27	14.31
417	Unfortunate Bubble Sort		gardengnome	10	15.93
339	Parking Lot			20	14.81
346	Long Decimal Fractions		csfpython	19	14.90
455	D flip-flop			5	16.99
353	Hurkle Hunter			18	14.98
243	Grille Encryption			32	14.03
290	Every Leaf on Every Tree		zelevin	26	14.37
415	Smallest Message		gardengnome	10	15.93
287	Palindrome Frog		csfpython	26	14.37
238	Bear Hunt			32	14.03
454	Multiplexer 4x4			5	16.99
268	Logic Transformation			28	14.25
340	Zeckendorf Lite		csfpython	19	14.90
217	Personality Swap			34	13.92
249	Turing Increment			30	14.13
312	The Shredder Conundrum		zelevin	22	14.65
261	Easter Bunnies 2D		gardengnome	28	14.25
393	Urban Planning		csfpython	12	15.64
367	Roguelike 1d			15	15.28
375	Space Invaders			14	15.40
298	Revoltle		zelevin	23	14.58
169	Automated Landing			38	13.74
331	Rotating Toy Display		csfpython	19	14.90
382	Die Throw Sequences		csfpython	13	15.51
432	Ball Bearing Collisions		csfpython	7	16.49
300	Run-Length Encoding			22	14.65
361	Rogue Mazes			15	15.28
395	Growth of Micro-Organisms		csfpython	11	15.78
295	Vigenere Cipher Cracker			22	14.65
275	Three Buckets			24	14.51
319	Tower of Hanoi Rules		csfpython	19	14.90
383	E2C2S - try harder!		gardengnome	12	15.64
363	Language Detector			14	15.40
250	Turing Clone			26	14.37
408	Mad Beaver in River Labyrinth			9	16.10
314	The Sorites Solution		zelevin	19	14.90
285	Rotate Matrix In Place			22	14.65
313	Seven Segment Decoder			19	14.90
398	Collecting Diamonds		csfpython	10	15.93
282	Predictable Board Game		csfpython	22	14.65
271	A Knight some Trolls and a Princess		csfpython	23	14.58
386	Advent Calendar Chocolate		gardengnome	11	15.78
424	New Towers of Hanoi		csfpython	7	16.49
344	Throwing Easter Eggs Part 2		gardengnome	15	15.28
462	Rota Boards		csfpython	3	17.69
402	Game of Stones		csfpython	9	16.10
260	Low Cost Road Network		csfpython	23	14.58
431	King and Rook Checkmate			6	16.72
358	Mandelbrot Set			13	15.51
419	Special Digits		csfpython	7	16.49
470	Shogi Engine			2	18.19
341	Zeckendorf Advanced		csfpython	14	15.40
448	Button Cycles		csfpython	4	17.30
231	Dice Black Jack			24	14.51
413	Tree Painting		csfpython	7	16.49
220	Neural Network Training			24	14.51
332	Easter Bunnies 2D Are Back		gardengnome	14	15.40
387	Big Numbers		csfpython	9	16.10
479	Robot and the Wall			1	18.90
456	Every Third Bit			3	17.69
213	Micro-Life	SK		24	14.51
222	Easter Eggs Advanced			23	14.58
443	Football League Tables		csfpython	4	17.30
266	Pancake Sorting			19	14.90
289	The Case of the Desperate Mastermind		zelevin	17	15.08
336	Currency Arbitrage			13	15.51
441	Max versus Min		csfpython	4	17.30
380	Treap Study			9	16.10
404	Methane Normalization		moxieman	7	16.49
416	Socket Server		testuser	6	16.72
391	Scout Proficiency Badges		csfpython	8	16.28
254	Rule 30 by Turing			19	14.90
263	Easter Bunnies 3D		gardengnome	18	14.98
262	Easter Bunnies 2D Advanced		gardengnome	18	14.98
221	XWords		quandray	21	14.73
410	Village Door Shuffle		csfpython	6	16.72
343	Village of Ticks			11	15.78
316	Apogee			13	15.51
422	Mabinogion Sheep		moxieman	5	16.99
235	Train Merge Advanced			19	14.90
288	Langton's Ant		csfpython	15	15.28
326	Sum Them Forth			12	15.64
311	The Mirror Maze		zelevin	13	15.51
365	Flower Border Arrangements		csfpython	9	16.10
309	Board Game Sequences		csfpython	13	15.51
350	Colourful Egg Sequences		gardengnome	10	15.93
267	Turing Maze			16	15.18
279	Two Buckets Advanced		csfpython	15	15.28
306	Line Drawing Algorithm			13	15.51
320	Accordion		pearlbarley	12	15.64
305	The Catacombs of Chronos		zelevin	13	15.51
333	Happy Triplets			11	15.78
276	Lucky Pairs		csfpython	15	15.28
304	Ordered Brackets		csfpython	13	15.51
303	Towers Under Cover			13	15.51
345	Elliptic Curves Basics			10	15.93
373	Railroad Rat		csfpython	8	16.28
430	Cutting Paper		csfpython	4	17.30
342	Adaptive Arithmetic Coding			10	15.93
369	Flappy Bird			8	16.28
264	Party Presents		csfpython	15	15.28
242	Comment Stripper			16	15.18
394	Many Shortest Routes		csfpython	6	16.72
224	Transposing List of Lists			17	15.08
237	Road Network Destruction			16	15.18
310	Board Game Sequences Advanced		csfpython	11	15.78
227	Hashtable Implementation			16	15.18
322	Gray Decoder			10	15.93
321	Hanoi Tower Heights		csfpython	10	15.93
327	Dobbin's Long Journey		csfpython	9	16.10
397	Trading Bot			5	16.99
325	Ultimate Sort Trial			9	16.10
378	Space Invaders Automation			6	16.72
302	Sound-Controlled Robot			10	15.93
283	Predictable Board Game on 10 Boards		csfpython	11	15.78
225	Hamurabi			14	15.40
252	Shadok and Gibis			12	15.64
328	Beep Beep Beep			8	16.28
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	16.99
236	Is the Earth Flat			11	15.78
280	Three Buckets Re-visited		csfpython	9	16.10
232	Shift Register Randomizer			11	15.78
273	Logic Glitches			9	16.10
226	Multiplicative Persistence Backtrace			11	15.78
248	Christmas Puzzle			9	16.10
348	Trick-Taking Game			5	16.99
240	Playfair Cipher Cracking			9	16.10
239	Foxes and Geese			9	16.10
396	Chocolate Triangles and BF		moxieman	3	17.69
272	Hexplore			7	16.49
355	Robots Game			4	17.30
228	Maze Mapping Robot			8	16.28
317	Launch to Orbit			5	16.99
356	Robots Game Autoplay			3	17.69
318	Launch to Orbit automated			2	18.19