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		55072	1.00
2	Sum in Loop	DE ES FR AR ZH RO RU SK		33717	1.85
3	Sums in Loop	DE ES FR AR ZH RO RU SK		25709	2.32
4	Minimum of Two	DE ES FR AR ZH RO RU SK		22392	2.56
5	Minimum of Three	DE ES FR AR ZH RO RU SK		20064	2.75
15	Maximum of array	DE ES AR ZH RO RU SK		17533	2.99
6	Rounding	DE ES AR ZH RO RU SK		16176	3.13
7	Fahrenheit to Celsius	DE ES AR ZH RO RU SK		15480	3.20
20	Vowel Count	DE ES AR ZH RO RU SK		12553	3.57
11	Sum of digits	DE ES RU ZH SK		12453	3.58
8	Arithmetic Progression	DE ES RU ZH SK		11646	3.70
41	Median of Three	DE ES AR ZH RO RU SK		10705	3.85
9	Triangles	DE ES RU ZH SK		11061	3.79
28	Body Mass Index	DE ES ZH RU SK		10568	3.87
13	Weighted sum of digits	DE ES RU ZH SK		10076	3.95
43	Dice Rolling	DE ES ZH RU SK		9085	4.13
16	Average of an array	DE ES RU SK		9526	4.05
30	Reverse String	DE ES RU SK		8973	4.15
17	Array Checksum	DE ES RU SK		8826	4.18
21	Array Counters	DE ES RU SK		8232	4.30
10	Linear Function	DE ES RU SK		7950	4.36
48	Collatz Sequence	DE ES RU SK		7179	4.54
12	Modulo and time difference	DE ES RU SK		7305	4.51
14	Modular Calculator	ES SK		6749	4.65
27	Bubble Sort	ES RU SK		6094	4.82
26	Greatest Common Divisor	ES SK RU		5942	4.87
18	Square Root	ES RU		5713	4.94
29	Sort with Indexes	RU		5501	5.00
50	Palindromes	DE ES RU SK		5044	5.15
23	Bubble in Array	ES RU		5276	5.07
52	Pythagorean Theorem	RU		4838	5.22
31	Rotate String	ES RU		5035	5.16
67	Fibonacci Sequence	RU		4365	5.40
68	Bicycle Race	ES RU		4337	5.41
57	Smoothing the Weather	ES RU		4368	5.40
24	Neumann's Random Generator	DE ES RU		4714	5.27
104	Triangle Area	ES		3432	5.82
35	Savings Calculator			4134	5.50
25	Linear Congruential Generator	RU		4087	5.52
44	Double Dice Roll	RU		3882	5.61
32	Josephus Problem	RU		3981	5.56
81	Bit Count	RU		3480	5.80
19	Matching Brackets	ES RU		3720	5.68
128	Combinations Counting			2723	6.22
58	Card Names			3308	5.88
47	Caesar Shift Cipher	SK		3391	5.84
49	Rock Paper Scissors			3341	5.87
55	Matching Words			3237	5.92
94	Fool's Day 2014	SK		2820	6.16
59	Bulls and Cows			2927	6.10
61	Prime Numbers Generation	RU		2881	6.12
22	Two Printers	ES RU		3094	6.00
42	Blackjack Counting			2659	6.26
120	Selection Sort			2078	6.69
38	Quadratic Equation			2444	6.41
33	Parity Control	RU		2407	6.44
53	King and Queen			2146	6.64
171	Tree Height Measurement			1485	7.28
34	Binary Search			2212	6.58
37	Mortgage Calculator	ZH		2078	6.69
45	Cards Shuffling	ZH		2024	6.74
69	Fibonacci Divisibility			1893	6.85
63	Integer Factorization	ZH		1817	6.93
46	Tic-Tac-Toe	ZH		1870	6.88
72	Funny Words Generator			1622	7.12
62	Prime Ranges			1659	7.08
437	Elections and Happiness			12	15.51
121	Insertion Sort			1377	7.41
75	Yacht or Dice Poker			1539	7.21
172	Cloud Altitude Measurement			1116	7.77
127	Anagrams			1292	7.52
438	Maze Generator			7	16.35
428	Broken Keyboard			46	13.28
134	Flying Text Screensaver			1196	7.65
39	Share Price Volatility			1551	7.20
156	Luhn Algorithm	SK		1017	7.93
114	Tricky Printing			1138	7.74
80	Duel Chances			1157	7.71
135	Variable Length Code			916	8.11
439	Power Sum of Digits		csfpython	2	18.06
36	Code Guesser	UA		1208	7.63
74	Clock Hands			1092	7.81
433	A Crime on Logic Island		csfpython	19	14.76
105	Convex Polygon Area			940	8.07
54	Pythagorean Triples			1062	7.86
429	Moving Average in Time			29	14.06
145	Modular Exponentiation			785	8.38
73	Hexagonal Grid			962	8.03
116	Summing Up			828	8.29
97	Girls and Pigs			858	8.23
187	Static Web Page			595	8.86
181	Reverse Polish Notation			605	8.83
188	Basics of HTML			569	8.94
436	Avoid the Grid Points		csfpython	8	16.15
122	QuickSort			696	8.59
98	Azimuth at Treasure Island			748	8.47
85	Rotation in 2D Space			753	8.45
51	Dungeons and Dragons Dice	UA		816	8.31
56	Life is Simple			787	8.38
40	Paths in the Grid	UA		802	8.34
434	A Crime on Logic Island Advanced		csfpython	11	15.65
70	Most Frequent Word			722	8.53
66	Caesar Cipher Cracker			721	8.53
88	Pitch and Notes			667	8.66
425	Explosive Breeding			27	14.18
108	Star Medals			606	8.83
435	Maze Mapping API-Robot			8	16.15
87	Tree Builder			609	8.82
95	Simple Linear Regression			593	8.87
60	Sweet Harvest			645	8.72
77	Point to Segment Distance			602	8.84
211	Information Entropy			379	9.64
207	Suffix Array			373	9.67
86	Brainfuck Interpreter			566	8.95
176	Say 100			407	9.52
91	Game of 2048			527	9.07
71	Fibonacci Divisibility Advanced			557	8.98
143	Extended Euclidean Algorithm			440	9.39
101	Gradient Calculation			491	9.20
195	Mul Two			353	9.77
119	Brain Fibo			461	9.31
191	Spaceship Weight Fraud			352	9.77
82	Levenshtein Distance			500	9.16
206	Base-32 Encoding			317	9.95
385	Number of steps in Euclidean Algorithm		gardengnome	73	12.49
89	Instrument Tuner			467	9.28
64	Maze Pathfinder			488	9.21
131	Four Pics One Word			390	9.60
377	Sum of Digits Divisibility			78	12.37
79	Cycles Detection			444	9.37
92	Binary Heap			420	9.47
189	Dynamic Web Page			302	10.04
150	Introducing Regexps			332	9.87
126	Sequence of Squares			359	9.74
136	Variable Length Code Unpack			347	9.80
83	Graph Generator			401	9.55
167	Copy Line			298	10.06
301	Skyscraper Price			151	11.24
170	Binary Search in Array			293	10.09
90	Lexicographic Permutations			380	9.64
427	Cheapest Bus Tickets			13	15.38
197	Loops in Assembly			259	10.30
78	Bezier Curves			385	9.62
154	Breadth First Search			300	10.05
117	Divide by Two			327	9.90
99	Uphill Shooting			340	9.83
65	Transitive Closure on Candy States			373	9.67
144	Modular Inverse			277	10.19
155	Depth First Search			262	10.28
174	Calculation of Pi			241	10.43
161	Topological Sorting			250	10.37
133	Billiard Ball			265	10.26
165	Safe Landing			234	10.48
140	Proper Bracket Sequences			253	10.34
366	Image Cutting		oezguery	60	12.82
76	Pawn Move Validator			299	10.06
190	Query String Parameters			204	10.72
96	Snake Arcade			280	10.17
184	Matches Picking		quandray	205	10.71
103	Easter Eggs			263	10.28
399	Methane Identification		moxieman	31	13.94
123	Knapsack of Integers			246	10.39
93	Starving Priority Queue			269	10.24
84	Dijkstra in the Network			270	10.23
130	Combinations with Repetitions			233	10.49
432	Ball Bearing Collisions		csfpython	5	16.85
125	Bogosort			234	10.48
323	Next Palindrome		csfpython	85	12.23
173	Chords of Music			195	10.79
414	MIDI Variable Length Numbers			18	14.85
418	Expected Number of Random Moves		moxieman	15	15.15
371	Pages to Print			49	13.17
109	Lucky Tickets			228	10.52
146	Color Cubes			202	10.73
360	Whisky Blending		csfpython	53	13.03
151	Word Ladders			193	10.81
411	Elo Ratings		moxieman	18	14.85
208	Neighborhood of a String			150	11.25
423	Russian Dolls		csfpython	10	15.80
129	Enumerating Combinations			200	10.75
164	Page Rank			174	10.99
138	Huffman Coding			188	10.86
139	Beam Balance and Masses			186	10.88
194	Convex Hull and Farmers			148	11.27
337	Introducing Zeckendorf		csfpython	61	12.79
201	Point in Polygon			142	11.34
199	Employees Web App			141	11.35
329	Roman Arithmetic		csfpython	63	12.74
374	Longest Common Subsequence			37	13.64
152	RSA Cryptography			164	11.09
137	Shannon-Fano Coding			172	11.01
192	Gangster Battles			140	11.37
431	King and Rook Checkmate			4	17.17
111	Necklace Count			178	10.95
368	Number Base Palindrome		csfpython	38	13.60
244	Introducing SQL			105	11.86
421	Princess and Tiger			9	15.96
401	Methane Rotation		moxieman	19	14.76
110	Lucky Tickets Advanced			168	11.05
168	Caesar meets BF			137	11.40
420	Life on a String		csfpython	9	15.96
245	Aggregations in SQL			95	12.03
253	Beautiful Line Chart			91	12.11
269	Fibonacci coding			83	12.27
400	Memory Check			18	14.85
364	Arthur Engel's Randomizer			35	13.74
372	String Minimization			31	13.94
162	Rubik's Cube			129	11.51
179	Look and Say binary			121	11.62
202	Dancing Pairs			110	11.78
148	Public Key Cryptography Intro			135	11.43
124	Knapsack Backtracking			145	11.31
198	Prn Hex Str			110	11.78
106	Random Search Optimization			152	11.22
407	River Labyrinth			14	15.26
214	Sick Travellers			101	11.93
182	Frodo and Black Riders			114	11.72
359	Find 3 Numbers		csfpython	35	13.74
177	Nim Game			113	11.74
294	Vigenere Cipher			62	12.77
160	Social Web Scraper			119	11.65
185	Simple 3D Scene			108	11.81
102	Travelling Salesman			141	11.35
246	Joins in SQL			79	12.35
384	Equal Hamming Distance		csfpython	22	14.52
157	Emirp primE			115	11.71
158	Hamming Codes			113	11.74
430	Cutting Paper		csfpython	3	17.56
159	Hard Life			105	11.86
381	Finding Squares		csfpython	21	14.59
258	Text Justification			66	12.66
265	Update in SQL			63	12.74
426	Weighted Sum of Digits 2		csfpython	4	17.17
412	Json Fix			9	15.96
196	Fibonacci Randomizer			86	12.21
406	Wormholes of Cygnus		moxieman	11	15.65
153	Fermat goes hacking RSA			100	11.95
291	Squirrels vs. Acorns		zelevin	51	13.10
100	Crossing the Road			116	11.69
277	The Adventure of Morse Code		zelevin	55	12.97
115	Gradient Descent for SLE			110	11.78
281	Basic Tokenizer			53	13.03
186	Simple 3D Scene (cont)			84	12.25
141	Sliding Window Search			99	11.96
409	Election Fever		csfpython	9	15.96
390	Card Pairing Solitaire			15	15.15
193	Maximum Flow			77	12.40
405	Three Friendly Knights		csfpython	10	15.80
166	Page Rank as Eigenvector			85	12.23
209	Suffix Array Advanced			71	12.53
210	Ticket Puzzle			70	12.56
142	LZ77 decompression			90	12.13
403	Hi-Lo dice game			10	15.80
203	Tic-Tac-Toe Minimax Algorithm			69	12.58
219	Neural Network Calculation			64	12.71
112	Travelling Salesman Inverted			94	12.05
113	Ground Zero			93	12.07
408	Mad Beaver in River Labyrinth			8	16.15
216	Cracking Linear Congruential Generator			62	12.77
351	Nicomachus			24	14.37
389	Binary Split Guessing Game		csfpython	13	15.38
274	Two Buckets			44	13.35
132	Stream Cipher Breaking			82	12.29
335	Venus Visible			27	14.18
163	Colliding Balls			72	12.51
413	Tree Painting		csfpython	6	16.58
175	Algae Robot			66	12.66
416	Socket Server		testuser	5	16.85
107	Knight's Tour			82	12.29
259	Easter Bunnies		gardengnome	44	13.35
205	Clustering the Stars			57	12.91
200	Fizz Buzz in Asm			57	12.91
293	Sums of Triplets			34	13.79
230	Move-To-Front Transform			49	13.17
334	Find all of the SETs		csfpython	24	14.37
376	Cartesian Tree Visualization			14	15.26
393	Urban Planning		csfpython	10	15.80
204	Wandering Star			54	13.00
315	Count the Common Factors		csfpython	28	14.11
241	Village Ways			45	13.31
388	Fibonacci Guessing Game			11	15.65
212	BCD to Hex			50	13.13
257	Missing Records in SQL			39	13.56
417	Unfortunate Bubble Sort		gardengnome	4	17.17
218	Rain Must Fall	DE		47	13.24
292	Factorial Trailing Zeroes			31	13.94
398	Collecting Diamonds		csfpython	8	16.15
379	Dice with Infinity Sides		telebashna	12	15.51
149	Prime Chains			60	12.82
392	Fixing an Anagram			9	15.96
386	Advent Calendar Chocolate		gardengnome	10	15.80
233	Language Study			41	13.47
395	Growth of Micro-Organisms		csfpython	8	16.15
415	Smallest Message		gardengnome	4	17.17
178	Maze of the Wumpus			51	13.10
307	The Problem of Too Many Clues		zelevin	25	14.30
147	Color Cubes Advanced			56	12.94
352	Hurkle			16	15.04
118	Maxit Single-Player			61	12.79
330	Easter Bunnies Are Back		gardengnome	20	14.67
424	New Towers of Hanoi		csfpython	2	18.06
180	Simple Game of Sticks			47	13.24
375	Space Invaders			11	15.65
223	Introducing Scheme			39	13.56
347	Unwanted Multiples		csfpython	16	15.04
363	Language Detector			13	15.38
367	Roguelike 1d			12	15.51
338	Throwing Easter Eggs		gardengnome	17	14.94
354	Too Many Divisors		csfpython	14	15.26
324	Merge Sort			19	14.76
353	Hurkle Hunter			14	15.26
382	Die Throw Sequences		csfpython	9	15.96
229	Burrows-Wheeler Transform			35	13.74
297	Collatz in the Range			23	14.44
255	LCM of a range			30	14.00
183	Connect Four			42	13.43
422	Mabinogion Sheep		moxieman	2	18.06
404	Methane Normalization		moxieman	5	16.85
247	Towers of Hanoi			31	13.94
349	Burrows		gardengnome	14	15.26
299	Tree Visualizer			22	14.52
296	Tree Value	RU	csfpython	22	14.52
346	Long Decimal Fractions		csfpython	14	15.26
358	Mandelbrot Set			12	15.51
383	E2C2S - try harder!		gardengnome	8	16.15
357	Ulam's Prime Spiral			12	15.51
331	Rotating Toy Display		csfpython	16	15.04
287	Palindrome Frog		csfpython	22	14.52
340	Zeckendorf Lite		csfpython	14	15.26
339	Parking Lot			14	15.26
284	Rotate Array In-Place			22	14.52
290	Every Leaf on Every Tree		zelevin	21	14.59
419	Special Digits		csfpython	2	18.06
270	Hexlife			23	14.44
362	Euclid, Manhattan and Chebyshev			10	15.80
298	Revoltle		zelevin	19	14.76
312	The Shredder Conundrum		zelevin	17	14.94
361	Rogue Mazes			10	15.80
217	Personality Swap			30	14.00
238	Bear Hunt			27	14.18
249	Turing Increment			25	14.30
234	Train Merge			27	14.18
256	Rook Jump Maze			24	14.37
261	Easter Bunnies 2D		gardengnome	23	14.44
313	Seven Segment Decoder			16	15.04
410	Village Door Shuffle		csfpython	3	17.56
387	Big Numbers		csfpython	6	16.58
243	Grille Encryption			25	14.30
402	Game of Stones		csfpython	4	17.17
286	Self-Printing Program			19	14.76
300	Run-Length Encoding			17	14.94
282	Predictable Board Game		csfpython	19	14.76
169	Automated Landing			33	13.84
344	Throwing Easter Eggs Part 2		gardengnome	11	15.65
285	Rotate Matrix In Place			18	14.85
268	Logic Transformation			20	14.67
275	Three Buckets			19	14.76
326	Sum Them Forth			12	15.51
378	Space Invaders Automation			6	16.58
271	A Knight some Trolls and a Princess		csfpython	18	14.85
341	Zeckendorf Advanced		csfpython	10	15.80
314	The Sorites Solution		zelevin	13	15.38
332	Easter Bunnies 2D Are Back		gardengnome	11	15.65
250	Turing Clone			20	14.67
213	Micro-Life	SK		24	14.37
394	Many Shortest Routes		csfpython	4	17.17
336	Currency Arbitrage			10	15.80
220	Neural Network Training			22	14.52
380	Treap Study			5	16.85
289	The Case of the Desperate Mastermind		zelevin	14	15.26
306	Line Drawing Algorithm			12	15.51
303	Towers Under Cover			12	15.51
260	Low Cost Road Network		csfpython	16	15.04
365	Flower Border Arrangements		csfpython	6	16.58
397	Trading Bot			3	17.56
343	Village of Ticks			8	16.15
288	Langton's Ant		csfpython	13	15.38
319	Tower of Hanoi Rules		csfpython	10	15.80
231	Dice Black Jack			18	14.85
396	Chocolate Triangles and BF		moxieman	3	17.56
263	Easter Bunnies 3D		gardengnome	15	15.15
262	Easter Bunnies 2D Advanced		gardengnome	15	15.15
350	Colourful Egg Sequences		gardengnome	7	16.35
316	Apogee			10	15.80
222	Easter Eggs Advanced			18	14.85
221	XWords		quandray	18	14.85
266	Pancake Sorting			14	15.26
254	Rule 30 by Turing			15	15.15
276	Lucky Pairs		csfpython	13	15.38
311	The Mirror Maze		zelevin	10	15.80
345	Elliptic Curves Basics			7	16.35
333	Happy Triplets			8	16.15
309	Board Game Sequences		csfpython	10	15.80
320	Accordion		pearlbarley	9	15.96
391	Scout Proficiency Badges		csfpython	3	17.56
279	Two Buckets Advanced		csfpython	12	15.51
325	Ultimate Sort Trial			8	16.15
235	Train Merge Advanced			15	15.15
295	Vigenere Cipher Cracker			10	15.80
242	Comment Stripper			14	15.26
305	The Catacombs of Chronos		zelevin	9	15.96
328	Beep Beep Beep			7	16.35
369	Flappy Bird			4	17.17
310	Board Game Sequences Advanced		csfpython	8	16.15
237	Road Network Destruction			13	15.38
308	Circle Drawing Algorithm			8	16.15
322	Gray Decoder			7	16.35
304	Ordered Brackets		csfpython	8	16.15
227	Hashtable Implementation			13	15.38
267	Turing Maze			10	15.80
215	Klotski	SK		13	15.38
327	Dobbin's Long Journey		csfpython	6	16.58
342	Adaptive Arithmetic Coding			5	16.85
373	Railroad Rat		csfpython	3	17.56
355	Robots Game			4	17.17
370	Jewels			3	17.56
264	Party Presents		csfpython	9	15.96
226	Multiplicative Persistence Backtrace			11	15.65
225	Hamurabi			11	15.65
224	Transposing List of Lists			11	15.65
252	Shadok and Gibis			9	15.96
248	Christmas Puzzle			9	15.96
283	Predictable Board Game on 10 Boards		csfpython	7	16.35
302	Sound-Controlled Robot			6	16.58
278	Polyomino Generation			7	16.35
356	Robots Game Autoplay			3	17.56
236	Is the Earth Flat			8	16.15
348	Trick-Taking Game			3	17.56
251	Radio Spies			7	16.35
321	Hanoi Tower Heights		csfpython	4	17.17
273	Logic Glitches			6	16.58
272	Hexplore			6	16.58
317	Launch to Orbit			4	17.17
240	Playfair Cipher Cracking			7	16.35
239	Foxes and Geese			7	16.35
232	Shift Register Randomizer			7	16.35
280	Three Buckets Re-visited		csfpython	5	16.85
228	Maze Mapping Robot			6	16.58
318	Launch to Orbit automated			2	18.06