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		59762	1.00
2	Sum in Loop	DE ES FR AR ZH RO RU SK		36226	1.87
3	Sums in Loop	DE ES FR AR ZH RO RU SK		27629	2.34
4	Minimum of Two	DE ES FR AR ZH RO RU SK		24082	2.58
5	Minimum of Three	DE ES FR AR ZH RO RU SK		21559	2.77
15	Maximum of array	DE ES AR ZH RO RU SK		18846	3.00
6	Rounding	DE ES AR ZH RO RU SK		17275	3.16
7	Fahrenheit to Celsius	DE ES AR ZH RO RU SK		16544	3.23
20	Vowel Count	DE ES AR ZH RO RU SK		13447	3.59
11	Sum of digits	DE ES RU ZH SK		13379	3.60
8	Arithmetic Progression	DE ES RU ZH SK		12565	3.71
41	Median of Three	DE ES AR ZH RO RU SK		11499	3.86
9	Triangles	DE ES RU ZH SK		12005	3.79
28	Body Mass Index	DE ES ZH RU SK		11374	3.88
13	Weighted sum of digits	DE ES RU ZH SK		10856	3.96
43	Dice Rolling	DE ES ZH RU SK		9768	4.15
16	Average of an array	DE ES RU SK		10295	4.06
30	Reverse String	DE ES RU SK		9728	4.15
17	Array Checksum	DE ES RU SK		9574	4.18
21	Array Counters	DE ES RU SK		8905	4.31
10	Linear Function	DE ES RU SK		8662	4.36
48	Collatz Sequence	DE ES RU SK		7733	4.55
12	Modulo and time difference	DE ES RU SK		7867	4.52
14	Modular Calculator	ES SK		7276	4.66
27	Bubble Sort	ES RU SK		6594	4.83
26	Greatest Common Divisor	ES SK RU		6419	4.88
18	Square Root	ES RU		6249	4.92
29	Sort with Indexes	RU		5959	5.00
50	Palindromes	DE ES RU SK		5511	5.14
23	Bubble in Array	ES RU		5715	5.08
52	Pythagorean Theorem	RU		5291	5.21
31	Rotate String	ES RU		5463	5.16
67	Fibonacci Sequence	RU		4750	5.40
68	Bicycle Race	ES RU		4717	5.41
24	Neumann's Random Generator	DE ES RU		5115	5.27
57	Smoothing the Weather	ES RU		4709	5.41
35	Savings Calculator			4525	5.48
104	Triangle Area	ES		3789	5.79
25	Linear Congruential Generator	RU		4472	5.50
32	Josephus Problem	RU		4364	5.55
44	Double Dice Roll	RU		4234	5.60
81	Bit Count	RU		3801	5.79
19	Matching Brackets	ES RU		4115	5.65
58	Card Names			3635	5.86
49	Rock Paper Scissors			3696	5.83
47	Caesar Shift Cipher	SK		3704	5.83
128	Combinations Counting			3001	6.20
55	Matching Words			3554	5.90
94	Fool's Day 2014	SK		3109	6.13
59	Bulls and Cows			3232	6.07
61	Prime Numbers Generation	RU		3179	6.10
22	Two Printers	ES RU		3439	5.96
42	Blackjack Counting			2956	6.22
120	Selection Sort			2336	6.63
38	Quadratic Equation			2739	6.35
33	Parity Control	RU		2670	6.40
53	King and Queen			2387	6.59
34	Binary Search			2476	6.53
171	Tree Height Measurement			1676	7.21
37	Mortgage Calculator	ZH		2319	6.64
45	Cards Shuffling	ZH		2262	6.69
69	Fibonacci Divisibility			2108	6.81
63	Integer Factorization	ZH		2028	6.88
46	Tic-Tac-Toe	ZH		2080	6.83
62	Prime Ranges			1858	7.03
72	Funny Words Generator			1800	7.08
121	Insertion Sort			1561	7.33
75	Yacht or Dice Poker			1698	7.18
172	Cloud Altitude Measurement			1273	7.69
39	Share Price Volatility			1743	7.14
127	Anagrams			1368	7.56
134	Flying Text Screensaver			1288	7.66
156	Luhn Algorithm	SK		1139	7.88
80	Duel Chances			1305	7.64
114	Tricky Printing			1199	7.79
509	Black and White Stone Game		csfpython	2	18.20
36	Code Guesser	UA		1401	7.52
74	Clock Hands			1229	7.75
135	Variable Length Code			1018	8.07
54	Pythagorean Triples			1215	7.77
105	Convex Polygon Area			1056	8.01
508	Black and White Squares		csfpython	4	17.31
73	Hexagonal Grid			1091	7.95
145	Modular Exponentiation			898	8.29
97	Girls and Pigs			969	8.16
116	Summing Up			877	8.33
181	Reverse Polish Notation			687	8.76
98	Azimuth at Treasure Island			844	8.40
122	QuickSort			783	8.53
51	Dungeons and Dragons Dice	UA		926	8.24
502	Chessboard			15	15.29
40	Paths in the Grid	UA		938	8.22
85	Rotation in 2D Space			847	8.39
56	Life is Simple			881	8.32
187	Static Web Page			618	8.94
188	Basics of HTML			589	9.02
66	Caesar Cipher Cracker			806	8.48
70	Most Frequent Word			798	8.50
88	Pitch and Notes			745	8.61
87	Tree Builder			714	8.69
60	Sweet Harvest			740	8.63
108	Star Medals			658	8.83
95	Simple Linear Regression			668	8.80
77	Point to Segment Distance			675	8.79
71	Fibonacci Divisibility Advanced			639	8.88
86	Brainfuck Interpreter			617	8.94
211	Information Entropy			427	9.58
91	Game of 2048			596	9.00
428	Broken Keyboard			114	11.86
207	Suffix Array			419	9.61
101	Gradient Calculation			548	9.15
507	Ticket Price Total		csfpython	3	17.70
504	Who are Backus and Naur			7	16.49
143	Extended Euclidean Algorithm			485	9.36
82	Levenshtein Distance			563	9.10
176	Say 100			428	9.58
191	Spaceship Weight Fraud			405	9.67
89	Instrument Tuner			522	9.23
154	Breadth First Search			441	9.52
206	Base-32 Encoding			374	9.81
119	Brain Fibo			481	9.37
64	Maze Pathfinder			547	9.15
79	Cycles Detection			520	9.24
195	Mul Two			374	9.81
92	Binary Heap			478	9.38
83	Graph Generator			479	9.38
155	Depth First Search			393	9.72
131	Four Pics One Word			413	9.64
301	Skyscraper Price			220	10.73
136	Variable Length Code Unpack			379	9.79
90	Lexicographic Permutations			425	9.59
78	Bezier Curves			437	9.54
65	Transitive Closure on Candy States			439	9.53
150	Introducing Regexps			352	9.91
189	Dynamic Web Page			311	10.13
126	Sequence of Squares			372	9.82
167	Copy Line			321	10.07
170	Binary Search in Array			312	10.12
385	Number of steps in Euclidean Algorithm		gardengnome	114	11.86
99	Uphill Shooting			370	9.83
480	Coin Payments		csfpython	26	14.38
161	Topological Sorting			312	10.12
117	Divide by Two			345	9.95
197	Loops in Assembly			273	10.35
144	Modular Inverse			316	10.10
377	Sum of Digits Divisibility			113	11.88
76	Pawn Move Validator			352	9.91
174	Calculation of Pi			270	10.37
505	Building Bridges		csfpython	3	17.70
93	Starving Priority Queue			331	10.02
429	Moving Average in Time			62	12.91
133	Billiard Ball			292	10.24
425	Explosive Breeding			65	12.83
96	Snake Arcade			316	10.10
140	Proper Bracket Sequences			280	10.31
506	A Strange Prime Function		csfpython	2	18.20
165	Safe Landing			256	10.47
495	Counting Arithmetic Progressions		csfpython	10	15.94
184	Matches Picking		quandray	237	10.60
103	Easter Eggs			294	10.23
84	Dijkstra in the Network			307	10.15
123	Knapsack of Integers			278	10.32
503	Dodecahedral Life			4	17.31
461	Lucky 7		csfpython	33	13.98
109	Lucky Tickets			274	10.35
173	Chords of Music			229	10.66
485	Magic 3		csfpython	16	15.18
130	Combinations with Repetitions			257	10.46
476	Prime Vowel Count		csfpython	22	14.66
125	Bogosort			255	10.47
190	Query String Parameters			210	10.81
366	Image Cutting		oezguery	90	12.27
444	White Rectangle			40	13.65
323	Next Palindrome		csfpython	115	11.85
146	Color Cubes			221	10.72
129	Enumerating Combinations			229	10.66
371	Pages to Print			82	12.43
253	Beautiful Line Chart			147	11.42
139	Beam Balance and Masses			211	10.80
151	Word Ladders			204	10.86
164	Page Rank			196	10.93
487	Reduce and Equalise		csfpython	12	15.65
208	Neighborhood of a String			169	11.18
138	Huffman Coding			206	10.84
360	Whisky Blending		csfpython	81	12.45
194	Convex Hull and Farmers			169	11.18
374	Longest Common Subsequence			72	12.65
437	Elections and Happiness			38	13.74
433	A Crime on Logic Island		csfpython	40	13.65
201	Point in Polygon			163	11.25
152	RSA Cryptography			185	11.03
111	Necklace Count			205	10.85
137	Shannon-Fano Coding			191	10.97
337	Introducing Zeckendorf		csfpython	88	12.31
102	Travelling Salesman			206	10.84
472	Unreachable Amounts		csfpython	18	14.99
110	Lucky Tickets Advanced			196	10.93
269	Fibonacci coding			117	11.82
471	Missing Digits		csfpython	18	14.99
192	Gangster Battles			153	11.36
481	Field Trip		csfpython	13	15.52
244	Introducing SQL			125	11.70
199	Employees Web App			144	11.46
399	Methane Identification		moxieman	50	13.28
329	Roman Arithmetic		csfpython	81	12.45
368	Number Base Palindrome		csfpython	63	12.88
501	Moving Stones		csfpython	3	17.70
494	Holiday Travel		csfpython	6	16.73
148	Public Key Cryptography Intro			157	11.31
124	Knapsack Backtracking			167	11.20
106	Random Search Optimization			173	11.14
496	Minimum Journey Cost		csfpython	5	16.99
489	TV Charity Fundraiser		csfpython	8	16.29
162	Rubik's Cube			145	11.45
294	Vigenere Cipher			89	12.29
202	Dancing Pairs			126	11.69
245	Aggregations in SQL			108	11.96
168	Caesar meets BF			139	11.52
214	Sick Travellers			119	11.79
468	The Garden of Words		zelevin	16	15.18
179	Look and Say binary			131	11.62
492	Fastest Clearance		csfpython	6	16.73
414	MIDI Variable Length Numbers			36	13.83
484	A Message from Deep Space		csfpython	9	16.11
182	Frodo and Black Riders			125	11.70
364	Arthur Engel's Randomizer			53	13.18
198	Prn Hex Str			113	11.88
158	Hamming Codes			127	11.68
177	Nim Game			120	11.77
160	Social Web Scraper			126	11.69
258	Text Justification			90	12.27
449	Space Pirates		csfpython	21	14.74
246	Joins in SQL			94	12.19
157	Emirp primE			125	11.70
359	Find 3 Numbers		csfpython	52	13.21
185	Simple 3D Scene			113	11.88
490	Circuit Board Connections		csfpython	6	16.73
498	Sum of Divisors Chaining			3	17.70
100	Crossing the Road			133	11.60
418	Expected Number of Random Moves		moxieman	29	14.20
159	Hard Life			112	11.89
153	Fermat goes hacking RSA			113	11.88
372	String Minimization			43	13.53
281	Basic Tokenizer			72	12.65
291	Squirrels vs. Acorns		zelevin	68	12.75
478	Robot Deliveries		csfpython	9	16.11
401	Methane Rotation		moxieman	33	13.98
115	Gradient Descent for SLE			121	11.76
497	Crazy Timer			3	17.70
411	Elo Ratings		moxieman	29	14.20
265	Update in SQL			73	12.63
324	Merge Sort			55	13.11
500	Enchanted Necklace		csfpython	2	18.20
277	The Adventure of Morse Code		zelevin	68	12.75
141	Sliding Window Search			108	11.96
493	Ternary Logic			4	17.31
384	Equal Hamming Distance		csfpython	36	13.83
112	Travelling Salesman Inverted			115	11.85
196	Fibonacci Randomizer			89	12.29
482	SS Numbers		csfpython	7	16.49
186	Simple 3D Scene (cont)			91	12.25
210	Ticket Puzzle			83	12.41
142	LZ77 decompression			102	12.05
166	Page Rank as Eigenvector			95	12.18
193	Maximum Flow			87	12.33
459	Number String Multiples of Thirteen		csfpython	13	15.52
499	Binary Frog		csfpython	2	18.20
488	Accurate Curve Fitting		csfpython	5	16.99
447	Fixed Product, Minimum Sum		csfpython	16	15.18
113	Ground Zero			105	12.00
209	Suffix Array Advanced			79	12.49
491	Lucky Number Scores		csfpython	4	17.31
274	Two Buckets			61	12.94
216	Cracking Linear Congruential Generator			75	12.58
203	Tic-Tac-Toe Minimax Algorithm			78	12.52
463	Crossing Towns		csfpython	11	15.79
427	Cheapest Bus Tickets			20	14.82
259	Easter Bunnies		gardengnome	62	12.91
219	Neural Network Calculation			72	12.65
434	A Crime on Logic Island Advanced		csfpython	18	14.99
466	Dictionary Entries		csfpython	10	15.94
107	Knight's Tour			99	12.11
351	Nicomachus			38	13.74
403	Hi-Lo dice game			25	14.45
452	Implication in Logic			13	15.52
132	Stream Cipher Breaking			90	12.27
381	Finding Squares		csfpython	30	14.14
460	Carlsdale Caverns		csfpython	11	15.79
241	Village Ways			62	12.91
163	Colliding Balls			80	12.47
458	Mountain Panorama		csfpython	11	15.79
400	Memory Check			24	14.51
175	Algae Robot			75	12.58
293	Sums of Triplets			48	13.34
469	Game of Generals			8	16.29
230	Move-To-Front Transform			60	12.96
205	Clustering the Stars			65	12.83
407	River Labyrinth			21	14.74
477	Lottery Balls		csfpython	6	16.73
406	Wormholes of Cygnus		moxieman	21	14.74
334	Find all of the SETs		csfpython	36	13.83
486	Two Colour Special Nim		csfpython	4	17.31
457	Railroad and Hamilton			10	15.94
335	Venus Visible			35	13.88
218	Rain Must Fall	DE		59	12.99
412	Json Fix			19	14.90
204	Wandering Star			61	12.94
315	Count the Common Factors		csfpython	38	13.74
255	LCM of a range			50	13.28
475	Medieval Medicine		zelevin	6	16.73
292	Factorial Trailing Zeroes			42	13.57
464	Graph to Loops Decomposition			8	16.29
474	Reachable Amounts		gardengnome	6	16.73
200	Fizz Buzz in Asm			59	12.99
390	Card Pairing Solitaire			22	14.66
149	Prime Chains			68	12.75
421	Princess and Tiger			16	15.18
467	Permutation Generator		csfpython	7	16.49
257	Missing Records in SQL			46	13.42
445	Formula 1			11	15.79
212	BCD to Hex			54	13.14
233	Language Study			50	13.28
118	Maxit Single-Player			71	12.68
307	The Problem of Too Many Clues		zelevin	36	13.83
388	Fibonacci Guessing Game			21	14.74
223	Introducing Scheme			50	13.28
442	Chomp			11	15.79
379	Dice with Infinity Sides		telebashna	22	14.66
453	SR latch			9	16.11
435	Maze Mapping API-Robot			12	15.65
180	Simple Game of Sticks			56	13.08
423	Russian Dolls		csfpython	14	15.40
446	Hangman			10	15.94
178	Maze of the Wumpus			56	13.08
247	Towers of Hanoi			44	13.49
147	Color Cubes Advanced			61	12.94
438	Maze Generator			11	15.79
420	Life on a String		csfpython	14	15.40
229	Burrows-Wheeler Transform			45	13.45
436	Avoid the Grid Points		csfpython	11	15.79
473	Skittles		csfpython	5	16.99
376	Cartesian Tree Visualization			20	14.82
426	Weighted Sum of Digits 2		csfpython	12	15.65
299	Tree Visualizer			31	14.09
270	Hexlife			35	13.88
450	Bead Games		csfpython	8	16.29
483	Sixes and Sevens		csfpython	3	17.70
352	Hurkle			22	14.66
392	Fixing an Anagram			16	15.18
357	Ulam's Prime Spiral			21	14.74
183	Connect Four			46	13.42
440	Mud Walker			9	16.11
347	Unwanted Multiples		csfpython	22	14.66
439	Power Sum of Digits		csfpython	9	16.11
389	Binary Split Guessing Game		csfpython	16	15.18
338	Throwing Easter Eggs		gardengnome	23	14.58
330	Easter Bunnies Are Back		gardengnome	24	14.51
409	Election Fever		csfpython	13	15.52
284	Rotate Array In-Place			30	14.14
297	Collatz in the Range			28	14.26
451	Maximize Toy Production		csfpython	7	16.49
296	Tree Value	RU	csfpython	28	14.26
354	Too Many Divisors		csfpython	20	14.82
234	Train Merge			36	13.83
405	Three Friendly Knights		csfpython	13	15.52
465	Red Blue Hackenbush		csfpython	5	16.99
349	Burrows		gardengnome	20	14.82
256	Rook Jump Maze			32	14.03
286	Self-Printing Program			28	14.26
417	Unfortunate Bubble Sort		gardengnome	11	15.79
362	Euclid, Manhattan and Chebyshev			18	14.99
346	Long Decimal Fractions		csfpython	20	14.82
353	Hurkle Hunter			19	14.90
243	Grille Encryption			33	13.98
455	D flip-flop			6	16.73
290	Every Leaf on Every Tree		zelevin	27	14.32
415	Smallest Message		gardengnome	11	15.79
454	Multiplexer 4x4			6	16.73
268	Logic Transformation			29	14.20
339	Parking Lot			20	14.82
238	Bear Hunt			32	14.03
287	Palindrome Frog		csfpython	26	14.38
393	Urban Planning		csfpython	13	15.52
217	Personality Swap			34	13.93
249	Turing Increment			30	14.14
375	Space Invaders			15	15.29
298	Revoltle		zelevin	24	14.51
340	Zeckendorf Lite		csfpython	19	14.90
169	Automated Landing			39	13.70
261	Easter Bunnies 2D		gardengnome	28	14.26
312	The Shredder Conundrum		zelevin	22	14.66
432	Ball Bearing Collisions		csfpython	8	16.29
300	Run-Length Encoding			23	14.58
395	Growth of Micro-Organisms		csfpython	12	15.65
367	Roguelike 1d			15	15.29
331	Rotating Toy Display		csfpython	19	14.90
313	Seven Segment Decoder			21	14.74
402	Game of Stones		csfpython	11	15.79
282	Predictable Board Game		csfpython	24	14.51
382	Die Throw Sequences		csfpython	13	15.52
363	Language Detector			15	15.29
361	Rogue Mazes			15	15.29
398	Collecting Diamonds		csfpython	11	15.79
295	Vigenere Cipher Cracker			22	14.66
285	Rotate Matrix In Place			23	14.58
275	Three Buckets			24	14.51
319	Tower of Hanoi Rules		csfpython	19	14.90
424	New Towers of Hanoi		csfpython	8	16.29
462	Rota Boards		csfpython	4	17.31
250	Turing Clone			26	14.38
383	E2C2S - try harder!		gardengnome	12	15.65
314	The Sorites Solution		zelevin	19	14.90
271	A Knight some Trolls and a Princess		csfpython	23	14.58
470	Shogi Engine			3	17.70
419	Special Digits		csfpython	8	16.29
358	Mandelbrot Set			14	15.40
408	Mad Beaver in River Labyrinth			9	16.11
386	Advent Calendar Chocolate		gardengnome	11	15.79
344	Throwing Easter Eggs Part 2		gardengnome	15	15.29
260	Low Cost Road Network		csfpython	23	14.58
413	Tree Painting		csfpython	8	16.29
231	Dice Black Jack			24	14.51
341	Zeckendorf Advanced		csfpython	14	15.40
431	King and Rook Checkmate			6	16.73
222	Easter Eggs Advanced			24	14.51
220	Neural Network Training			24	14.51
404	Methane Normalization		moxieman	8	16.29
332	Easter Bunnies 2D Are Back		gardengnome	14	15.40
213	Micro-Life	SK		24	14.51
221	XWords		quandray	23	14.58
266	Pancake Sorting			19	14.90
289	The Case of the Desperate Mastermind		zelevin	17	15.08
387	Big Numbers		csfpython	9	16.11
448	Button Cycles		csfpython	4	17.31
336	Currency Arbitrage			13	15.52
410	Village Door Shuffle		csfpython	7	16.49
422	Mabinogion Sheep		moxieman	6	16.73
254	Rule 30 by Turing			19	14.90
316	Apogee			14	15.40
380	Treap Study			9	16.11
263	Easter Bunnies 3D		gardengnome	18	14.99
262	Easter Bunnies 2D Advanced		gardengnome	18	14.99
235	Train Merge Advanced			20	14.82
326	Sum Them Forth			13	15.52
391	Scout Proficiency Badges		csfpython	8	16.29
311	The Mirror Maze		zelevin	14	15.40
443	Football League Tables		csfpython	4	17.31
416	Socket Server		testuser	6	16.73
456	Every Third Bit			3	17.70
279	Two Buckets Advanced		csfpython	16	15.18
305	The Catacombs of Chronos		zelevin	14	15.40
441	Max versus Min		csfpython	4	17.31
288	Langton's Ant		csfpython	15	15.29
343	Village of Ticks			11	15.79
267	Turing Maze			16	15.18
309	Board Game Sequences		csfpython	13	15.52
394	Many Shortest Routes		csfpython	7	16.49
365	Flower Border Arrangements		csfpython	9	16.11
350	Colourful Egg Sequences		gardengnome	10	15.94
306	Line Drawing Algorithm			13	15.52
320	Accordion		pearlbarley	12	15.65
276	Lucky Pairs		csfpython	15	15.29
304	Ordered Brackets		csfpython	13	15.52
333	Happy Triplets			11	15.79
303	Towers Under Cover			13	15.52
345	Elliptic Curves Basics			10	15.94
373	Railroad Rat		csfpython	8	16.29
342	Adaptive Arithmetic Coding			10	15.94
264	Party Presents		csfpython	15	15.29
479	Robot and the Wall			1	18.90
369	Flappy Bird			8	16.29
322	Gray Decoder			11	15.79
242	Comment Stripper			16	15.18
224	Transposing List of Lists			17	15.08
430	Cutting Paper		csfpython	4	17.31
237	Road Network Destruction			16	15.18
378	Space Invaders Automation			7	16.49
227	Hashtable Implementation			16	15.18
310	Board Game Sequences Advanced		csfpython	11	15.79
325	Ultimate Sort Trial			10	15.94
321	Hanoi Tower Heights		csfpython	10	15.94
302	Sound-Controlled Robot			11	15.79
225	Hamurabi			15	15.29
327	Dobbin's Long Journey		csfpython	9	16.11
397	Trading Bot			5	16.99
283	Predictable Board Game on 10 Boards		csfpython	11	15.79
252	Shadok and Gibis			12	15.65
370	Jewels			6	16.73
308	Circle Drawing Algorithm			9	16.11
328	Beep Beep Beep			8	16.29
215	Klotski	SK		13	15.52
236	Is the Earth Flat			12	15.65
278	Polyomino Generation			10	15.94
232	Shift Register Randomizer			12	15.65
273	Logic Glitches			10	15.94
251	Radio Spies			11	15.79
280	Three Buckets Re-visited		csfpython	9	16.11
348	Trick-Taking Game			6	16.73
226	Multiplicative Persistence Backtrace			11	15.79
248	Christmas Puzzle			10	15.94
355	Robots Game			5	16.99
272	Hexplore			8	16.29
240	Playfair Cipher Cracking			9	16.11
239	Foxes and Geese			9	16.11
396	Chocolate Triangles and BF		moxieman	3	17.70
228	Maze Mapping Robot			8	16.29
317	Launch to Orbit			5	16.99
356	Robots Game Autoplay			3	17.70
318	Launch to Orbit automated			2	18.20