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		57191	1.00
2	Sum in Loop	DE ES FR AR ZH RO RU SK		34732	1.87
3	Sums in Loop	DE ES FR AR ZH RO RU SK		26441	2.34
4	Minimum of Two	DE ES FR AR ZH RO RU SK		23028	2.58
5	Minimum of Three	DE ES FR AR ZH RO RU SK		20620	2.77
15	Maximum of array	DE ES AR ZH RO RU SK		18019	3.01
6	Rounding	DE ES AR ZH RO RU SK		16527	3.16
7	Fahrenheit to Celsius	DE ES AR ZH RO RU SK		15834	3.23
20	Vowel Count	DE ES AR ZH RO RU SK		12841	3.59
11	Sum of digits	DE ES RU ZH SK		12752	3.61
8	Arithmetic Progression	DE ES RU ZH SK		11940	3.72
41	Median of Three	DE ES AR ZH RO RU SK		10940	3.87
9	Triangles	DE ES RU ZH SK		11333	3.81
28	Body Mass Index	DE ES ZH RU SK		10814	3.89
13	Weighted sum of digits	DE ES RU ZH SK		10299	3.98
43	Dice Rolling	DE ES ZH RU SK		9270	4.16
16	Average of an array	DE ES RU SK		9754	4.07
30	Reverse String	DE ES RU SK		9190	4.18
17	Array Checksum	DE ES RU SK		9031	4.21
21	Array Counters	DE ES RU SK		8405	4.33
10	Linear Function	DE ES RU SK		8126	4.39
48	Collatz Sequence	DE ES RU SK		7340	4.57
12	Modulo and time difference	DE ES RU SK		7456	4.54
14	Modular Calculator	ES SK		6894	4.68
27	Bubble Sort	ES RU SK		6235	4.85
26	Greatest Common Divisor	ES SK RU		6067	4.90
18	Square Root	ES RU		5872	4.95
29	Sort with Indexes	RU		5622	5.03
50	Palindromes	DE ES RU SK		5171	5.17
23	Bubble in Array	ES RU		5391	5.10
52	Pythagorean Theorem	RU		4962	5.25
31	Rotate String	ES RU		5150	5.18
67	Fibonacci Sequence	RU		4466	5.43
68	Bicycle Race	ES RU		4434	5.44
57	Smoothing the Weather	ES RU		4460	5.43
24	Neumann's Random Generator	DE ES RU		4817	5.30
35	Savings Calculator			4232	5.52
104	Triangle Area	ES		3530	5.84
25	Linear Congruential Generator	RU		4182	5.54
44	Double Dice Roll	RU		3963	5.64
32	Josephus Problem	RU		4066	5.59
81	Bit Count	RU		3556	5.83
19	Matching Brackets	ES RU		3827	5.70
58	Card Names			3390	5.91
128	Combinations Counting			2797	6.24
47	Caesar Shift Cipher	SK		3469	5.87
49	Rock Paper Scissors			3420	5.89
55	Matching Words			3314	5.95
94	Fool's Day 2014	SK		2898	6.18
59	Bulls and Cows			3007	6.12
61	Prime Numbers Generation	RU		2955	6.15
22	Two Printers	ES RU		3184	6.02
42	Blackjack Counting			2734	6.28
120	Selection Sort			2153	6.70
38	Quadratic Equation			2516	6.43
33	Parity Control	RU		2473	6.46
53	King and Queen			2214	6.65
34	Binary Search			2281	6.60
171	Tree Height Measurement			1539	7.28
37	Mortgage Calculator	ZH		2142	6.71
45	Cards Shuffling	ZH		2087	6.75
69	Fibonacci Divisibility			1952	6.87
63	Integer Factorization	ZH		1870	6.94
46	Tic-Tac-Toe	ZH		1930	6.89
461	Lucky 7		csfpython	16	15.11
72	Funny Words Generator			1669	7.14
62	Prime Ranges			1709	7.10
121	Insertion Sort			1428	7.41
75	Yacht or Dice Poker			1583	7.23
464	Graph to Loops Decomposition			3	17.62
172	Cloud Altitude Measurement			1164	7.76
127	Anagrams			1317	7.55
39	Share Price Volatility			1596	7.22
134	Flying Text Screensaver			1219	7.68
156	Luhn Algorithm	SK		1056	7.93
114	Tricky Printing			1160	7.77
80	Duel Chances			1197	7.72
36	Code Guesser	UA		1249	7.64
135	Variable Length Code			948	8.12
74	Clock Hands			1122	7.83
105	Convex Polygon Area			977	8.07
54	Pythagorean Triples			1097	7.87
145	Modular Exponentiation			821	8.37
73	Hexagonal Grid			999	8.03
463	Crossing Towns		csfpython	4	17.23
97	Girls and Pigs			894	8.22
116	Summing Up			842	8.33
181	Reverse Polish Notation			631	8.83
187	Static Web Page			603	8.91
98	Azimuth at Treasure Island			778	8.46
122	QuickSort			716	8.61
188	Basics of HTML			576	8.98
85	Rotation in 2D Space			786	8.45
51	Dungeons and Dragons Dice	UA		841	8.33
56	Life is Simple			809	8.40
40	Paths in the Grid	UA		838	8.33
428	Broken Keyboard			68	12.67
66	Caesar Cipher Cracker			743	8.54
70	Most Frequent Word			731	8.57
88	Pitch and Notes			686	8.68
108	Star Medals			613	8.88
459	Number String Multiples of Thirteen		csfpython	9	16.03
95	Simple Linear Regression			615	8.87
87	Tree Builder			626	8.84
60	Sweet Harvest			664	8.74
77	Point to Segment Distance			623	8.85
460	Carlsdale Caverns		csfpython	7	16.42
211	Information Entropy			389	9.67
86	Brainfuck Interpreter			580	8.97
207	Suffix Array			381	9.70
91	Game of 2048			546	9.08
71	Fibonacci Divisibility Advanced			573	8.99
176	Say 100			411	9.57
143	Extended Euclidean Algorithm			452	9.40
101	Gradient Calculation			509	9.20
82	Levenshtein Distance			516	9.18
119	Brain Fibo			466	9.35
195	Mul Two			359	9.80
191	Spaceship Weight Fraud			364	9.78
206	Base-32 Encoding			332	9.94
89	Instrument Tuner			478	9.31
64	Maze Pathfinder			501	9.23
79	Cycles Detection			465	9.36
131	Four Pics One Word			398	9.63
92	Binary Heap			438	9.46
429	Moving Average in Time			41	13.54
189	Dynamic Web Page			304	10.09
83	Graph Generator			421	9.53
136	Variable Length Code Unpack			356	9.82
150	Introducing Regexps			336	9.92
126	Sequence of Squares			361	9.79
385	Number of steps in Euclidean Algorithm		gardengnome	84	12.31
301	Skyscraper Price			172	11.08
444	White Rectangle			21	14.66
90	Lexicographic Permutations			391	9.66
78	Bezier Curves			397	9.63
170	Binary Search in Array			300	10.12
167	Copy Line			303	10.10
425	Explosive Breeding			39	13.62
458	Mountain Panorama		csfpython	6	16.65
154	Breadth First Search			310	10.06
197	Loops in Assembly			266	10.32
377	Sum of Digits Divisibility			85	12.29
65	Transitive Closure on Candy States			388	9.67
117	Divide by Two			329	9.96
99	Uphill Shooting			345	9.87
144	Modular Inverse			283	10.22
457	Railroad and Hamilton			6	16.65
155	Depth First Search			269	10.30
161	Topological Sorting			262	10.35
174	Calculation of Pi			250	10.43
133	Billiard Ball			273	10.28
437	Elections and Happiness			22	14.58
165	Safe Landing			245	10.47
76	Pawn Move Validator			315	10.03
140	Proper Bracket Sequences			260	10.36
96	Snake Arcade			288	10.19
184	Matches Picking		quandray	213	10.71
190	Query String Parameters			206	10.77
123	Knapsack of Integers			255	10.40
93	Starving Priority Queue			277	10.25
103	Easter Eggs			269	10.30
84	Dijkstra in the Network			282	10.22
130	Combinations with Repetitions			242	10.49
125	Bogosort			239	10.51
173	Chords of Music			202	10.80
452	Implication in Logic			8	16.21
433	A Crime on Logic Island		csfpython	21	14.66
366	Image Cutting		oezguery	65	12.75
462	Rota Boards		csfpython	1	18.83
109	Lucky Tickets			236	10.53
323	Next Palindrome		csfpython	92	12.16
146	Color Cubes			207	10.76
151	Word Ladders			200	10.82
449	Space Pirates		csfpython	9	16.03
371	Pages to Print			57	12.98
129	Enumerating Combinations			206	10.77
447	Fixed Product, Minimum Sum		csfpython	10	15.86
164	Page Rank			182	10.98
208	Neighborhood of a String			154	11.27
138	Huffman Coding			194	10.87
139	Beam Balance and Masses			192	10.89
399	Methane Identification		moxieman	38	13.67
360	Whisky Blending		csfpython	61	12.86
453	SR latch			6	16.65
194	Convex Hull and Farmers			157	11.23
201	Point in Polygon			150	11.31
152	RSA Cryptography			171	11.09
137	Shannon-Fano Coding			178	11.02
454	Multiplexer 4x4			5	16.92
199	Employees Web App			141	11.42
337	Introducing Zeckendorf		csfpython	67	12.70
192	Gangster Battles			143	11.40
111	Necklace Count			182	10.98
244	Introducing SQL			110	11.85
329	Roman Arithmetic		csfpython	67	12.70
455	D flip-flop			4	17.23
110	Lucky Tickets Advanced			175	11.05
253	Beautiful Line Chart			103	11.96
446	Hangman			8	16.21
374	Longest Common Subsequence			42	13.50
168	Caesar meets BF			137	11.47
269	Fibonacci coding			90	12.19
411	Elo Ratings		moxieman	24	14.44
245	Aggregations in SQL			99	12.03
368	Number Base Palindrome		csfpython	43	13.46
148	Public Key Cryptography Intro			142	11.41
124	Knapsack Backtracking			152	11.29
162	Rubik's Cube			133	11.52
202	Dancing Pairs			115	11.77
106	Random Search Optimization			157	11.23
179	Look and Say binary			124	11.64
214	Sick Travellers			105	11.93
294	Vigenere Cipher			71	12.60
182	Frodo and Black Riders			118	11.73
198	Prn Hex Str			111	11.83
102	Travelling Salesman			146	11.36
160	Social Web Scraper			122	11.67
177	Nim Game			115	11.77
435	Maze Mapping API-Robot			11	15.71
372	String Minimization			36	13.76
158	Hamming Codes			121	11.68
364	Arthur Engel's Randomizer			39	13.62
427	Cheapest Bus Tickets			14	15.32
185	Simple 3D Scene			109	11.86
434	A Crime on Logic Island Advanced		csfpython	11	15.71
246	Joins in SQL			83	12.33
157	Emirp primE			117	11.74
418	Expected Number of Random Moves		moxieman	17	15.01
359	Find 3 Numbers		csfpython	39	13.62
414	MIDI Variable Length Numbers			18	14.91
438	Maze Generator			9	16.03
440	Mud Walker			8	16.21
401	Methane Rotation		moxieman	22	14.58
451	Maximize Toy Production		csfpython	4	17.23
159	Hard Life			107	11.90
258	Text Justification			71	12.60
436	Avoid the Grid Points		csfpython	9	16.03
153	Fermat goes hacking RSA			105	11.93
400	Memory Check			21	14.66
456	Every Third Bit			2	18.12
265	Update in SQL			65	12.75
196	Fibonacci Randomizer			87	12.25
100	Crossing the Road			118	11.73
115	Gradient Descent for SLE			112	11.82
277	The Adventure of Morse Code		zelevin	59	12.92
291	Squirrels vs. Acorns		zelevin	54	13.07
281	Basic Tokenizer			57	12.98
141	Sliding Window Search			101	11.99
186	Simple 3D Scene (cont)			85	12.29
442	Chomp			6	16.65
193	Maximum Flow			81	12.37
166	Page Rank as Eigenvector			89	12.21
445	Formula 1			5	16.92
142	LZ77 decompression			95	12.10
384	Equal Hamming Distance		csfpython	23	14.51
209	Suffix Array Advanced			73	12.55
423	Russian Dolls		csfpython	11	15.71
381	Finding Squares		csfpython	23	14.51
210	Ticket Puzzle			71	12.60
203	Tic-Tac-Toe Minimax Algorithm			72	12.58
112	Travelling Salesman Inverted			97	12.06
407	River Labyrinth			15	15.21
113	Ground Zero			96	12.08
219	Neural Network Calculation			66	12.73
439	Power Sum of Digits		csfpython	6	16.65
450	Bead Games		csfpython	3	17.62
216	Cracking Linear Congruential Generator			65	12.75
132	Stream Cipher Breaking			84	12.31
421	Princess and Tiger			10	15.86
274	Two Buckets			46	13.34
351	Nicomachus			27	14.24
163	Colliding Balls			73	12.55
420	Life on a String		csfpython	10	15.86
432	Ball Bearing Collisions		csfpython	7	16.42
107	Knight's Tour			85	12.29
175	Algae Robot			68	12.67
230	Move-To-Front Transform			54	13.07
259	Easter Bunnies		gardengnome	47	13.30
241	Village Ways			50	13.20
205	Clustering the Stars			58	12.95
390	Card Pairing Solitaire			16	15.11
412	Json Fix			11	15.71
335	Venus Visible			28	14.18
200	Fizz Buzz in Asm			58	12.95
406	Wormholes of Cygnus		moxieman	12	15.57
293	Sums of Triplets			36	13.76
218	Rain Must Fall	DE		52	13.13
204	Wandering Star			55	13.04
334	Find all of the SETs		csfpython	27	14.24
403	Hi-Lo dice game			12	15.57
431	King and Rook Checkmate			6	16.65
212	BCD to Hex			51	13.17
426	Weighted Sum of Digits 2		csfpython	7	16.42
315	Count the Common Factors		csfpython	29	14.12
149	Prime Chains			62	12.83
379	Dice with Infinity Sides		telebashna	16	15.11
257	Missing Records in SQL			40	13.58
292	Factorial Trailing Zeroes			33	13.90
233	Language Study			43	13.46
178	Maze of the Wumpus			53	13.10
147	Color Cubes Advanced			58	12.95
389	Binary Split Guessing Game		csfpython	13	15.44
405	Three Friendly Knights		csfpython	10	15.86
118	Maxit Single-Player			62	12.83
376	Cartesian Tree Visualization			15	15.21
409	Election Fever		csfpython	9	16.03
307	The Problem of Too Many Clues		zelevin	27	14.24
448	Button Cycles		csfpython	2	18.12
255	LCM of a range			36	13.76
180	Simple Game of Sticks			49	13.23
330	Easter Bunnies Are Back		gardengnome	22	14.58
324	Merge Sort			23	14.51
223	Introducing Scheme			40	13.58
229	Burrows-Wheeler Transform			37	13.71
183	Connect Four			44	13.42
408	Mad Beaver in River Labyrinth			8	16.21
338	Throwing Easter Eggs		gardengnome	19	14.83
299	Tree Visualizer			25	14.37
247	Towers of Hanoi			33	13.90
388	Fibonacci Guessing Game			11	15.71
354	Too Many Divisors		csfpython	16	15.11
393	Urban Planning		csfpython	10	15.86
347	Unwanted Multiples		csfpython	17	15.01
352	Hurkle			16	15.11
297	Collatz in the Range			24	14.44
296	Tree Value	RU	csfpython	24	14.44
375	Space Invaders			12	15.57
284	Rotate Array In-Place			25	14.37
270	Hexlife			27	14.24
416	Socket Server		testuser	6	16.65
415	Smallest Message		gardengnome	6	16.65
386	Advent Calendar Chocolate		gardengnome	10	15.86
363	Language Detector			13	15.44
290	Every Leaf on Every Tree		zelevin	23	14.51
392	Fixing an Anagram			9	16.03
443	Football League Tables		csfpython	2	18.12
340	Zeckendorf Lite		csfpython	16	15.11
339	Parking Lot			16	15.11
287	Palindrome Frog		csfpython	23	14.51
413	Tree Painting		csfpython	6	16.65
398	Collecting Diamonds		csfpython	8	16.21
353	Hurkle Hunter			14	15.32
367	Roguelike 1d			12	15.57
382	Die Throw Sequences		csfpython	10	15.86
238	Bear Hunt			29	14.12
312	The Shredder Conundrum		zelevin	19	14.83
349	Burrows		gardengnome	14	15.32
256	Rook Jump Maze			26	14.30
217	Personality Swap			31	14.01
395	Growth of Micro-Organisms		csfpython	8	16.21
286	Self-Printing Program			22	14.58
402	Game of Stones		csfpython	7	16.42
331	Rotating Toy Display		csfpython	16	15.11
362	Euclid, Manhattan and Chebyshev			12	15.57
243	Grille Encryption			27	14.24
346	Long Decimal Fractions		csfpython	14	15.32
298	Revoltle		zelevin	20	14.74
234	Train Merge			28	14.18
169	Automated Landing			36	13.76
417	Unfortunate Bubble Sort		gardengnome	5	16.92
249	Turing Increment			26	14.30
441	Max versus Min		csfpython	2	18.12
261	Easter Bunnies 2D		gardengnome	24	14.44
383	E2C2S - try harder!		gardengnome	9	16.03
358	Mandelbrot Set			12	15.57
357	Ulam's Prime Spiral			12	15.57
282	Predictable Board Game		csfpython	21	14.66
268	Logic Transformation			22	14.58
361	Rogue Mazes			11	15.71
300	Run-Length Encoding			18	14.91
430	Cutting Paper		csfpython	3	17.62
271	A Knight some Trolls and a Princess		csfpython	21	14.66
313	Seven Segment Decoder			16	15.11
285	Rotate Matrix In Place			19	14.83
410	Village Door Shuffle		csfpython	5	16.92
419	Special Digits		csfpython	4	17.23
275	Three Buckets			19	14.83
387	Big Numbers		csfpython	7	16.42
250	Turing Clone			21	14.66
213	Micro-Life	SK		24	14.44
344	Throwing Easter Eggs Part 2		gardengnome	11	15.71
394	Many Shortest Routes		csfpython	6	16.65
404	Methane Normalization		moxieman	5	16.92
319	Tower of Hanoi Rules		csfpython	13	15.44
295	Vigenere Cipher Cracker			15	15.21
220	Neural Network Training			22	14.58
326	Sum Them Forth			12	15.57
422	Mabinogion Sheep		moxieman	3	17.62
314	The Sorites Solution		zelevin	13	15.44
260	Low Cost Road Network		csfpython	18	14.91
332	Easter Bunnies 2D Are Back		gardengnome	11	15.71
221	XWords		quandray	21	14.66
341	Zeckendorf Advanced		csfpython	10	15.86
231	Dice Black Jack			19	14.83
336	Currency Arbitrage			10	15.86
289	The Case of the Desperate Mastermind		zelevin	14	15.32
262	Easter Bunnies 2D Advanced		gardengnome	16	15.11
380	Treap Study			6	16.65
222	Easter Eggs Advanced			19	14.83
306	Line Drawing Algorithm			12	15.57
254	Rule 30 by Turing			16	15.11
316	Apogee			11	15.71
378	Space Invaders Automation			6	16.65
303	Towers Under Cover			12	15.57
365	Flower Border Arrangements		csfpython	7	16.42
276	Lucky Pairs		csfpython	14	15.32
263	Easter Bunnies 3D		gardengnome	15	15.21
288	Langton's Ant		csfpython	13	15.44
266	Pancake Sorting			14	15.32
345	Elliptic Curves Basics			8	16.21
343	Village of Ticks			8	16.21
424	New Towers of Hanoi		csfpython	2	18.12
242	Comment Stripper			15	15.21
311	The Mirror Maze		zelevin	10	15.86
309	Board Game Sequences		csfpython	10	15.86
279	Two Buckets Advanced		csfpython	12	15.57
235	Train Merge Advanced			15	15.21
350	Colourful Egg Sequences		gardengnome	7	16.42
320	Accordion		pearlbarley	9	16.03
333	Happy Triplets			8	16.21
391	Scout Proficiency Badges		csfpython	4	17.23
327	Dobbin's Long Journey		csfpython	8	16.21
325	Ultimate Sort Trial			8	16.21
370	Jewels			5	16.92
305	The Catacombs of Chronos		zelevin	9	16.03
237	Road Network Destruction			13	15.44
267	Turing Maze			11	15.71
227	Hashtable Implementation			13	15.44
397	Trading Bot			3	17.62
328	Beep Beep Beep			7	16.42
310	Board Game Sequences Advanced		csfpython	8	16.21
396	Chocolate Triangles and BF		moxieman	3	17.62
308	Circle Drawing Algorithm			8	16.21
342	Adaptive Arithmetic Coding			6	16.65
252	Shadok and Gibis			11	15.71
215	Klotski	SK		13	15.44
322	Gray Decoder			7	16.42
304	Ordered Brackets		csfpython	8	16.21
264	Party Presents		csfpython	10	15.86
225	Hamurabi			12	15.57
369	Flappy Bird			4	17.23
226	Multiplicative Persistence Backtrace			11	15.71
224	Transposing List of Lists			11	15.71
283	Predictable Board Game on 10 Boards		csfpython	8	16.21
321	Hanoi Tower Heights		csfpython	6	16.65
278	Polyomino Generation			8	16.21
251	Radio Spies			9	16.03
248	Christmas Puzzle			9	16.03
355	Robots Game			4	17.23
239	Foxes and Geese			9	16.03
373	Railroad Rat		csfpython	3	17.62
280	Three Buckets Re-visited		csfpython	7	16.42
302	Sound-Controlled Robot			6	16.65
232	Shift Register Randomizer			9	16.03
348	Trick-Taking Game			4	17.23
272	Hexplore			7	16.42
240	Playfair Cipher Cracking			8	16.21
236	Is the Earth Flat			8	16.21
356	Robots Game Autoplay			3	17.62
273	Logic Glitches			6	16.65
317	Launch to Orbit			4	17.23
228	Maze Mapping Robot			6	16.65
318	Launch to Orbit automated			2	18.12