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		59415	1.00
2	Sum in Loop	DE ES FR AR ZH RO RU SK		36021	1.87
3	Sums in Loop	DE ES FR AR ZH RO RU SK		27464	2.34
4	Minimum of Two	DE ES FR AR ZH RO RU SK		23939	2.58
5	Minimum of Three	DE ES FR AR ZH RO RU SK		21437	2.77
15	Maximum of array	DE ES AR ZH RO RU SK		18737	3.00
6	Rounding	DE ES AR ZH RO RU SK		17178	3.16
7	Fahrenheit to Celsius	DE ES AR ZH RO RU SK		16455	3.23
20	Vowel Count	DE ES AR ZH RO RU SK		13360	3.59
11	Sum of digits	DE ES RU ZH SK		13291	3.60
8	Arithmetic Progression	DE ES RU ZH SK		12488	3.71
41	Median of Three	DE ES AR ZH RO RU SK		11436	3.86
9	Triangles	DE ES RU ZH SK		11931	3.79
28	Body Mass Index	DE ES ZH RU SK		11303	3.88
13	Weighted sum of digits	DE ES RU ZH SK		10790	3.96
43	Dice Rolling	DE ES ZH RU SK		9711	4.15
16	Average of an array	DE ES RU SK		10229	4.06
30	Reverse String	DE ES RU SK		9660	4.16
17	Array Checksum	DE ES RU SK		9506	4.18
21	Array Counters	DE ES RU SK		8847	4.31
10	Linear Function	DE ES RU SK		8597	4.36
48	Collatz Sequence	DE ES RU SK		7673	4.56
12	Modulo and time difference	DE ES RU SK		7805	4.53
14	Modular Calculator	ES SK		7220	4.66
27	Bubble Sort	ES RU SK		6546	4.83
26	Greatest Common Divisor	ES SK RU		6372	4.88
18	Square Root	ES RU		6197	4.93
29	Sort with Indexes	RU		5909	5.01
50	Palindromes	DE ES RU SK		5455	5.15
23	Bubble in Array	ES RU		5657	5.08
52	Pythagorean Theorem	RU		5248	5.22
31	Rotate String	ES RU		5421	5.16
67	Fibonacci Sequence	RU		4702	5.41
68	Bicycle Race	ES RU		4670	5.42
24	Neumann's Random Generator	DE ES RU		5055	5.28
57	Smoothing the Weather	ES RU		4658	5.42
35	Savings Calculator			4480	5.49
104	Triangle Area	ES		3738	5.80
25	Linear Congruential Generator	RU		4413	5.52
32	Josephus Problem	RU		4297	5.56
44	Double Dice Roll	RU		4180	5.61
81	Bit Count	RU		3745	5.80
19	Matching Brackets	ES RU		4063	5.66
58	Card Names			3581	5.88
49	Rock Paper Scissors			3634	5.85
47	Caesar Shift Cipher	SK		3641	5.85
128	Combinations Counting			2944	6.22
55	Matching Words			3500	5.92
94	Fool's Day 2014	SK		3057	6.15
59	Bulls and Cows			3168	6.09
61	Prime Numbers Generation	RU		3111	6.12
22	Two Printers	ES RU		3372	5.98
42	Blackjack Counting			2890	6.25
120	Selection Sort			2284	6.66
38	Quadratic Equation			2676	6.39
33	Parity Control	RU		2604	6.43
53	King and Queen			2335	6.62
34	Binary Search			2417	6.56
171	Tree Height Measurement			1620	7.26
37	Mortgage Calculator	ZH		2261	6.68
45	Cards Shuffling	ZH		2210	6.72
69	Fibonacci Divisibility			2054	6.84
63	Integer Factorization	ZH		1972	6.92
46	Tic-Tac-Toe	ZH		2030	6.86
62	Prime Ranges			1807	7.07
72	Funny Words Generator			1746	7.13
121	Insertion Sort			1522	7.36
75	Yacht or Dice Poker			1653	7.22
172	Cloud Altitude Measurement			1224	7.74
39	Share Price Volatility			1684	7.19
127	Anagrams			1356	7.57
134	Flying Text Screensaver			1257	7.70
156	Luhn Algorithm	SK		1104	7.92
114	Tricky Printing			1184	7.80
80	Duel Chances			1255	7.70
36	Code Guesser	UA		1347	7.58
74	Clock Hands			1180	7.81
135	Variable Length Code			990	8.11
54	Pythagorean Triples			1170	7.82
105	Convex Polygon Area			1020	8.06
495	Counting Arithmetic Progressions		csfpython	4	17.30
73	Hexagonal Grid			1051	8.01
145	Modular Exponentiation			862	8.35
97	Girls and Pigs			942	8.20
116	Summing Up			862	8.35
181	Reverse Polish Notation			664	8.80
98	Azimuth at Treasure Island			817	8.44
122	QuickSort			755	8.58
51	Dungeons and Dragons Dice	UA		896	8.28
85	Rotation in 2D Space			824	8.43
496	Minimum Journey Cost		csfpython	1	18.89
40	Paths in the Grid	UA		907	8.26
187	Static Web Page			613	8.94
56	Life is Simple			858	8.36
188	Basics of HTML			583	9.03
70	Most Frequent Word			775	8.54
66	Caesar Cipher Cracker			782	8.52
88	Pitch and Notes			725	8.65
87	Tree Builder			690	8.74
494	Holiday Travel		csfpython	4	17.30
108	Star Medals			636	8.88
60	Sweet Harvest			714	8.68
95	Simple Linear Regression			650	8.84
77	Point to Segment Distance			659	8.82
428	Broken Keyboard			102	12.04
86	Brainfuck Interpreter			600	8.98
211	Information Entropy			414	9.62
71	Fibonacci Divisibility Advanced			614	8.94
91	Game of 2048			579	9.04
207	Suffix Array			403	9.67
101	Gradient Calculation			537	9.17
480	Coin Payments		csfpython	22	14.65
143	Extended Euclidean Algorithm			473	9.39
176	Say 100			424	9.58
82	Levenshtein Distance			546	9.14
191	Spaceship Weight Fraud			389	9.73
89	Instrument Tuner			511	9.26
119	Brain Fibo			472	9.40
485	Magic 3		csfpython	14	15.39
64	Maze Pathfinder			535	9.18
206	Base-32 Encoding			359	9.87
195	Mul Two			370	9.82
79	Cycles Detection			498	9.30
92	Binary Heap			467	9.41
131	Four Pics One Word			407	9.65
154	Breadth First Search			381	9.77
83	Graph Generator			455	9.46
487	Reduce and Equalise		csfpython	10	15.93
476	Prime Vowel Count		csfpython	22	14.65
301	Skyscraper Price			204	10.85
136	Variable Length Code Unpack			369	9.82
90	Lexicographic Permutations			413	9.63
78	Bezier Curves			424	9.58
155	Depth First Search			345	9.94
150	Introducing Regexps			346	9.93
189	Dynamic Web Page			307	10.14
126	Sequence of Squares			366	9.84
65	Transitive Closure on Candy States			424	9.58
385	Number of steps in Euclidean Algorithm		gardengnome	106	11.98
167	Copy Line			311	10.12
170	Binary Search in Array			306	10.15
99	Uphill Shooting			364	9.85
461	Lucky 7		csfpython	32	14.02
197	Loops in Assembly			269	10.37
161	Topological Sorting			299	10.19
117	Divide by Two			336	9.99
144	Modular Inverse			304	10.16
377	Sum of Digits Divisibility			102	12.04
429	Moving Average in Time			56	13.07
76	Pawn Move Validator			343	9.95
174	Calculation of Pi			262	10.42
425	Explosive Breeding			57	13.04
492	Fastest Clearance		csfpython	3	17.69
93	Starving Priority Queue			321	10.06
133	Billiard Ball			284	10.28
140	Proper Bracket Sequences			274	10.34
96	Snake Arcade			307	10.14
165	Safe Landing			252	10.48
481	Field Trip		csfpython	11	15.78
493	Ternary Logic			2	18.19
184	Matches Picking		quandray	225	10.68
103	Easter Eggs			283	10.28
123	Knapsack of Integers			268	10.38
84	Dijkstra in the Network			293	10.22
484	A Message from Deep Space		csfpython	8	16.28
173	Chords of Music			221	10.71
130	Combinations with Repetitions			249	10.50
190	Query String Parameters			208	10.82
472	Unreachable Amounts		csfpython	16	15.17
444	White Rectangle			35	13.87
125	Bogosort			247	10.52
109	Lucky Tickets			256	10.46
471	Missing Digits		csfpython	16	15.17
323	Next Palindrome		csfpython	107	11.96
366	Image Cutting		oezguery	80	12.46
146	Color Cubes			215	10.76
129	Enumerating Combinations			222	10.70
371	Pages to Print			74	12.60
151	Word Ladders			202	10.87
164	Page Rank			192	10.95
139	Beam Balance and Masses			206	10.83
208	Neighborhood of a String			166	11.20
253	Beautiful Line Chart			138	11.52
437	Elections and Happiness			33	13.97
374	Longest Common Subsequence			68	12.74
138	Huffman Coding			200	10.88
360	Whisky Blending		csfpython	75	12.57
194	Convex Hull and Farmers			165	11.22
201	Point in Polygon			158	11.29
482	SS Numbers		csfpython	7	16.48
433	A Crime on Logic Island		csfpython	33	13.97
478	Robot Deliveries		csfpython	9	16.10
152	RSA Cryptography			180	11.06
337	Introducing Zeckendorf		csfpython	82	12.42
468	The Garden of Words		zelevin	14	15.39
137	Shannon-Fano Coding			185	11.02
111	Necklace Count			198	10.90
102	Travelling Salesman			199	10.89
489	TV Charity Fundraiser		csfpython	3	17.69
399	Methane Identification		moxieman	48	13.33
491	Lucky Number Scores		csfpython	2	18.19
192	Gangster Battles			149	11.39
110	Lucky Tickets Advanced			187	11.00
244	Introducing SQL			121	11.75
199	Employees Web App			142	11.47
269	Fibonacci coding			106	11.98
368	Number Base Palindrome		csfpython	59	12.98
329	Roman Arithmetic		csfpython	77	12.53
148	Public Key Cryptography Intro			153	11.35
106	Random Search Optimization			168	11.18
124	Knapsack Backtracking			159	11.28
294	Vigenere Cipher			86	12.34
245	Aggregations in SQL			107	11.96
490	Circuit Board Connections		csfpython	2	18.19
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
198	Prn Hex Str			113	11.87
449	Space Pirates		csfpython	17	15.07
177	Nim Game			119	11.78
160	Social Web Scraper			125	11.69
414	MIDI Variable Length Numbers			30	14.13
158	Hamming Codes			125	11.69
246	Joins in SQL			92	12.22
459	Number String Multiples of Thirteen		csfpython	13	15.51
364	Arthur Engel's Randomizer			48	13.33
185	Simple 3D Scene			113	11.87
157	Emirp primE			123	11.72
359	Find 3 Numbers		csfpython	49	13.30
258	Text Justification			85	12.36
466	Dictionary Entries		csfpython	10	15.93
463	Crossing Towns		csfpython	11	15.78
477	Lottery Balls		csfpython	6	16.72
401	Methane Rotation		moxieman	32	14.02
418	Expected Number of Random Moves		moxieman	26	14.37
372	String Minimization			41	13.60
488	Accurate Curve Fitting		csfpython	2	18.19
159	Hard Life			111	11.90
153	Fermat goes hacking RSA			111	11.90
411	Elo Ratings		moxieman	27	14.31
100	Crossing the Road			128	11.65
447	Fixed Product, Minimum Sum		csfpython	15	15.28
475	Medieval Medicine		zelevin	6	16.72
265	Update in SQL			72	12.64
384	Equal Hamming Distance		csfpython	34	13.92
115	Gradient Descent for SLE			117	11.81
458	Mountain Panorama		csfpython	11	15.78
324	Merge Sort			52	13.20
291	Squirrels vs. Acorns		zelevin	62	12.90
281	Basic Tokenizer			65	12.82
474	Reachable Amounts		gardengnome	6	16.72
141	Sliding Window Search			107	11.96
427	Cheapest Bus Tickets			20	14.81
277	The Adventure of Morse Code		zelevin	65	12.82
196	Fibonacci Randomizer			89	12.28
460	Carlsdale Caverns		csfpython	10	15.93
186	Simple 3D Scene (cont)			90	12.26
452	Implication in Logic			12	15.64
193	Maximum Flow			86	12.34
469	Game of Generals			7	16.48
210	Ticket Puzzle			81	12.44
483	Sixes and Sevens		csfpython	3	17.69
166	Page Rank as Eigenvector			93	12.20
112	Travelling Salesman Inverted			108	11.95
142	LZ77 decompression			99	12.10
209	Suffix Array Advanced			79	12.48
464	Graph to Loops Decomposition			8	16.28
486	Two Colour Special Nim		csfpython	2	18.19
434	A Crime on Logic Island Advanced		csfpython	16	15.17
113	Ground Zero			102	12.04
216	Cracking Linear Congruential Generator			74	12.60
467	Permutation Generator		csfpython	7	16.48
203	Tic-Tac-Toe Minimax Algorithm			77	12.53
219	Neural Network Calculation			72	12.64
274	Two Buckets			57	13.04
457	Railroad and Hamilton			9	16.10
400	Memory Check			23	14.57
351	Nicomachus			35	13.87
132	Stream Cipher Breaking			88	12.30
381	Finding Squares		csfpython	27	14.31
107	Knight's Tour			93	12.20
163	Colliding Balls			79	12.48
259	Easter Bunnies		gardengnome	56	13.07
241	Village Ways			60	12.95
403	Hi-Lo dice game			21	14.73
175	Algae Robot			74	12.60
445	Formula 1			11	15.78
205	Clustering the Stars			65	12.82
407	River Labyrinth			19	14.89
230	Move-To-Front Transform			58	13.01
293	Sums of Triplets			44	13.48
406	Wormholes of Cygnus		moxieman	19	14.89
335	Venus Visible			34	13.92
446	Hangman			10	15.93
315	Count the Common Factors		csfpython	38	13.73
218	Rain Must Fall	DE		58	13.01
435	Maze Mapping API-Robot			12	15.64
334	Find all of the SETs		csfpython	33	13.97
473	Skittles		csfpython	4	17.30
204	Wandering Star			60	12.95
292	Factorial Trailing Zeroes			41	13.60
453	SR latch			8	16.28
200	Fizz Buzz in Asm			59	12.98
412	Json Fix			16	15.17
255	LCM of a range			47	13.37
421	Princess and Tiger			14	15.39
436	Avoid the Grid Points		csfpython	11	15.78
390	Card Pairing Solitaire			20	14.81
149	Prime Chains			67	12.77
257	Missing Records in SQL			45	13.44
450	Bead Games		csfpython	8	16.28
212	BCD to Hex			53	13.17
423	Russian Dolls		csfpython	13	15.51
438	Maze Generator			10	15.93
233	Language Study			48	13.33
307	The Problem of Too Many Clues		zelevin	34	13.92
118	Maxit Single-Player			68	12.74
442	Chomp			9	16.10
379	Dice with Infinity Sides		telebashna	20	14.81
180	Simple Game of Sticks			55	13.10
440	Mud Walker			9	16.10
223	Introducing Scheme			47	13.37
147	Color Cubes Advanced			60	12.95
451	Maximize Toy Production		csfpython	7	16.48
178	Maze of the Wumpus			54	13.13
439	Power Sum of Digits		csfpython	9	16.10
247	Towers of Hanoi			42	13.56
426	Weighted Sum of Digits 2		csfpython	11	15.78
420	Life on a String		csfpython	12	15.64
376	Cartesian Tree Visualization			19	14.89
229	Burrows-Wheeler Transform			43	13.52
357	Ulam's Prime Spiral			21	14.73
299	Tree Visualizer			30	14.13
465	Red Blue Hackenbush		csfpython	4	17.30
347	Unwanted Multiples		csfpython	22	14.65
352	Hurkle			21	14.73
338	Throwing Easter Eggs		gardengnome	23	14.57
330	Easter Bunnies Are Back		gardengnome	24	14.50
183	Connect Four			46	13.41
409	Election Fever		csfpython	12	15.64
354	Too Many Divisors		csfpython	20	14.81
388	Fibonacci Guessing Game			15	15.28
270	Hexlife			32	14.02
297	Collatz in the Range			28	14.25
455	D flip-flop			5	16.98
349	Burrows		gardengnome	20	14.81
405	Three Friendly Knights		csfpython	12	15.64
284	Rotate Array In-Place			29	14.19
454	Multiplexer 4x4			5	16.98
296	Tree Value	RU	csfpython	27	14.31
389	Binary Split Guessing Game		csfpython	14	15.39
392	Fixing an Anagram			13	15.51
234	Train Merge			34	13.92
346	Long Decimal Fractions		csfpython	19	14.89
290	Every Leaf on Every Tree		zelevin	26	14.37
243	Grille Encryption			32	14.02
256	Rook Jump Maze			30	14.13
287	Palindrome Frog		csfpython	26	14.37
286	Self-Printing Program			26	14.37
238	Bear Hunt			32	14.02
340	Zeckendorf Lite		csfpython	19	14.89
339	Parking Lot			19	14.89
362	Euclid, Manhattan and Chebyshev			16	15.17
417	Unfortunate Bubble Sort		gardengnome	9	16.10
249	Turing Increment			30	14.13
217	Personality Swap			34	13.92
393	Urban Planning		csfpython	12	15.64
353	Hurkle Hunter			17	15.07
312	The Shredder Conundrum		zelevin	22	14.65
432	Ball Bearing Collisions		csfpython	7	16.48
375	Space Invaders			14	15.39
261	Easter Bunnies 2D		gardengnome	28	14.25
268	Logic Transformation			27	14.31
415	Smallest Message		gardengnome	9	16.10
298	Revoltle		zelevin	23	14.57
331	Rotating Toy Display		csfpython	19	14.89
169	Automated Landing			38	13.73
395	Growth of Micro-Organisms		csfpython	11	15.78
300	Run-Length Encoding			22	14.65
367	Roguelike 1d			14	15.39
462	Rota Boards		csfpython	3	17.69
295	Vigenere Cipher Cracker			22	14.65
382	Die Throw Sequences		csfpython	12	15.64
408	Mad Beaver in River Labyrinth			9	16.10
363	Language Detector			14	15.39
398	Collecting Diamonds		csfpython	10	15.93
470	Shogi Engine			2	18.19
479	Robot and the Wall			1	18.89
361	Rogue Mazes			14	15.39
313	Seven Segment Decoder			19	14.89
285	Rotate Matrix In Place			22	14.65
275	Three Buckets			23	14.57
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	14.57
431	King and Rook Checkmate			6	16.72
250	Turing Clone			25	14.44
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
358	Mandelbrot Set			13	15.51
386	Advent Calendar Chocolate		gardengnome	10	15.93
456	Every Third Bit			3	17.69
341	Zeckendorf Advanced		csfpython	14	15.39
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
260	Low Cost Road Network		csfpython	21	14.73
443	Football League Tables		csfpython	4	17.30
220	Neural Network Training			24	14.50
441	Max versus Min		csfpython	4	17.30
213	Micro-Life	SK		24	14.50
222	Easter Eggs Advanced			23	14.57
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
387	Big Numbers		csfpython	8	16.28
289	The Case of the Desperate Mastermind		zelevin	16	15.17
448	Button Cycles		csfpython	3	17.69
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
422	Mabinogion Sheep		moxieman	5	16.98
221	XWords		quandray	21	14.73
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
391	Scout Proficiency Badges		csfpython	7	16.48
311	The Mirror Maze		zelevin	13	15.51
350	Colourful Egg Sequences		gardengnome	10	15.93
430	Cutting Paper		csfpython	4	17.30
320	Accordion		pearlbarley	12	15.64
279	Two Buckets Advanced		csfpython	15	15.28
306	Line Drawing Algorithm			13	15.51
305	The Catacombs of Chronos		zelevin	13	15.51
276	Lucky Pairs		csfpython	15	15.28
345	Elliptic Curves Basics			10	15.93
303	Towers Under Cover			13	15.51
267	Turing Maze			15	15.28
309	Board Game Sequences		csfpython	12	15.64
365	Flower Border Arrangements		csfpython	8	16.28
394	Many Shortest Routes		csfpython	6	16.72
304	Ordered Brackets		csfpython	12	15.64
333	Happy Triplets			10	15.93
242	Comment Stripper			16	15.17
224	Transposing List of Lists			17	15.07
237	Road Network Destruction			16	15.17
342	Adaptive Arithmetic Coding			9	16.10
264	Party Presents		csfpython	14	15.39
227	Hashtable Implementation			16	15.17
322	Gray Decoder			10	15.93
369	Flappy Bird			7	16.48
397	Trading Bot			5	16.98
310	Board Game Sequences Advanced		csfpython	10	15.93
378	Space Invaders Automation			6	16.72
327	Dobbin's Long Journey		csfpython	9	16.10
325	Ultimate Sort Trial			9	16.10
321	Hanoi Tower Heights		csfpython	9	16.10
373	Railroad Rat		csfpython	6	16.72
302	Sound-Controlled Robot			10	15.93
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
283	Predictable Board Game on 10 Boards		csfpython	10	15.93
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