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		59753	1.00
2	Sum in Loop	DE ES FR AR ZH RO RU SK		36221	1.87
3	Sums in Loop	DE ES FR AR ZH RO RU SK		27623	2.34
4	Minimum of Two	DE ES FR AR ZH RO RU SK		24077	2.58
5	Minimum of Three	DE ES FR AR ZH RO RU SK		21554	2.77
15	Maximum of array	DE ES AR ZH RO RU SK		18842	3.00
6	Rounding	DE ES AR ZH RO RU SK		17271	3.16
7	Fahrenheit to Celsius	DE ES AR ZH RO RU SK		16540	3.23
20	Vowel Count	DE ES AR ZH RO RU SK		13443	3.59
11	Sum of digits	DE ES RU ZH SK		13375	3.60
8	Arithmetic Progression	DE ES RU ZH SK		12562	3.71
41	Median of Three	DE ES AR ZH RO RU SK		11498	3.86
9	Triangles	DE ES RU ZH SK		12002	3.79
28	Body Mass Index	DE ES ZH RU SK		11371	3.88
13	Weighted sum of digits	DE ES RU ZH SK		10854	3.96
43	Dice Rolling	DE ES ZH RU SK		9767	4.15
16	Average of an array	DE ES RU SK		10293	4.06
30	Reverse String	DE ES RU SK		9727	4.15
17	Array Checksum	DE ES RU SK		9573	4.18
21	Array Counters	DE ES RU SK		8903	4.31
10	Linear Function	DE ES RU SK		8661	4.35
48	Collatz Sequence	DE ES RU SK		7732	4.55
12	Modulo and time difference	DE ES RU SK		7866	4.52
14	Modular Calculator	ES SK		7275	4.66
27	Bubble Sort	ES RU SK		6591	4.83
26	Greatest Common Divisor	ES SK RU		6417	4.88
18	Square Root	ES RU		6248	4.92
29	Sort with Indexes	RU		5956	5.01
50	Palindromes	DE ES RU SK		5509	5.14
23	Bubble in Array	ES RU		5711	5.08
52	Pythagorean Theorem	RU		5290	5.21
31	Rotate String	ES RU		5461	5.16
67	Fibonacci Sequence	RU		4750	5.40
68	Bicycle Race	ES RU		4715	5.41
24	Neumann's Random Generator	DE ES RU		5112	5.27
57	Smoothing the Weather	ES RU		4707	5.41
35	Savings Calculator			4522	5.48
104	Triangle Area	ES		3788	5.79
25	Linear Congruential Generator	RU		4469	5.50
32	Josephus Problem	RU		4360	5.55
44	Double Dice Roll	RU		4234	5.60
81	Bit Count	RU		3800	5.79
19	Matching Brackets	ES RU		4112	5.65
58	Card Names			3634	5.86
49	Rock Paper Scissors			3695	5.83
47	Caesar Shift Cipher	SK		3701	5.83
128	Combinations Counting			3000	6.20
55	Matching Words			3553	5.90
94	Fool's Day 2014	SK		3108	6.13
59	Bulls and Cows			3231	6.07
61	Prime Numbers Generation	RU		3178	6.10
22	Two Printers	ES RU		3435	5.96
42	Blackjack Counting			2954	6.22
120	Selection Sort			2333	6.63
38	Quadratic Equation			2736	6.36
33	Parity Control	RU		2665	6.40
53	King and Queen			2385	6.59
34	Binary Search			2473	6.53
171	Tree Height Measurement			1673	7.21
37	Mortgage Calculator	ZH		2316	6.65
45	Cards Shuffling	ZH		2258	6.69
69	Fibonacci Divisibility			2105	6.81
63	Integer Factorization	ZH		2024	6.88
46	Tic-Tac-Toe	ZH		2076	6.84
62	Prime Ranges			1854	7.03
72	Funny Words Generator			1797	7.09
121	Insertion Sort			1557	7.34
75	Yacht or Dice Poker			1695	7.19
172	Cloud Altitude Measurement			1269	7.69
39	Share Price Volatility			1739	7.14
127	Anagrams			1368	7.56
134	Flying Text Screensaver			1286	7.67
156	Luhn Algorithm	SK		1136	7.88
80	Duel Chances			1303	7.64
114	Tricky Printing			1197	7.79
36	Code Guesser	UA		1397	7.52
74	Clock Hands			1226	7.75
135	Variable Length Code			1013	8.08
54	Pythagorean Triples			1211	7.77
105	Convex Polygon Area			1053	8.01
73	Hexagonal Grid			1089	7.96
145	Modular Exponentiation			896	8.29
97	Girls and Pigs			967	8.16
116	Summing Up			875	8.34
181	Reverse Polish Notation			685	8.76
98	Azimuth at Treasure Island			842	8.40
122	QuickSort			781	8.53
51	Dungeons and Dragons Dice	UA		922	8.24
509	Black and White Stone Game		csfpython	1	18.90
508	Black and White Squares		csfpython	3	17.70
40	Paths in the Grid	UA		935	8.22
85	Rotation in 2D Space			844	8.40
56	Life is Simple			878	8.33
187	Static Web Page			618	8.94
502	Chessboard			14	15.40
188	Basics of HTML			589	9.02
70	Most Frequent Word			796	8.50
66	Caesar Cipher Cracker			803	8.48
88	Pitch and Notes			743	8.62
87	Tree Builder			712	8.69
60	Sweet Harvest			738	8.63
108	Star Medals			657	8.83
95	Simple Linear Regression			667	8.81
77	Point to Segment Distance			674	8.79
86	Brainfuck Interpreter			617	8.94
71	Fibonacci Divisibility Advanced			638	8.88
211	Information Entropy			426	9.58
91	Game of 2048			595	9.00
428	Broken Keyboard			114	11.86
207	Suffix Array			419	9.61
101	Gradient Calculation			548	9.15
504	Who are Backus and Naur			7	16.49
507	Ticket Price Total		csfpython	3	17.70
143	Extended Euclidean Algorithm			485	9.36
82	Levenshtein Distance			562	9.10
176	Say 100			428	9.58
191	Spaceship Weight Fraud			405	9.67
154	Breadth First Search			441	9.52
89	Instrument Tuner			521	9.23
119	Brain Fibo			481	9.37
206	Base-32 Encoding			373	9.81
64	Maze Pathfinder			546	9.15
79	Cycles Detection			518	9.24
195	Mul Two			374	9.81
92	Binary Heap			478	9.38
83	Graph Generator			478	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			378	9.79
90	Lexicographic Permutations			424	9.59
78	Bezier Curves			435	9.55
65	Transitive Closure on Candy States			438	9.54
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			350	9.92
174	Calculation of Pi			270	10.37
505	Building Bridges		csfpython	3	17.70
93	Starving Priority Queue			330	10.03
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
123	Knapsack of Integers			278	10.32
84	Dijkstra in the Network			306	10.16
503	Dodecahedral Life			4	17.31
461	Lucky 7		csfpython	33	13.98
109	Lucky Tickets			273	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			81	12.45
253	Beautiful Line Chart			147	11.42
151	Word Ladders			204	10.86
164	Page Rank			196	10.93
139	Beam Balance and Masses			210	10.81
487	Reduce and Equalise		csfpython	12	15.65
208	Neighborhood of a String			169	11.18
138	Huffman Coding			205	10.85
360	Whisky Blending		csfpython	80	12.47
194	Convex Hull and Farmers			168	11.19
437	Elections and Happiness			38	13.74
374	Longest Common Subsequence			71	12.68
201	Point in Polygon			162	11.26
152	RSA Cryptography			185	11.03
433	A Crime on Logic Island		csfpython	39	13.70
337	Introducing Zeckendorf		csfpython	88	12.31
111	Necklace Count			204	10.86
137	Shannon-Fano Coding			189	10.99
102	Travelling Salesman			205	10.85
472	Unreachable Amounts		csfpython	18	14.99
110	Lucky Tickets Advanced			196	10.93
471	Missing Digits		csfpython	18	14.99
269	Fibonacci coding			116	11.83
192	Gangster Battles			153	11.36
481	Field Trip		csfpython	13	15.52
244	Introducing SQL			124	11.72
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			166	11.21
106	Random Search Optimization			173	11.14
489	TV Charity Fundraiser		csfpython	8	16.29
496	Minimum Journey Cost		csfpython	5	16.99
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
497	Crazy Timer			3	17.70
115	Gradient Descent for SLE			120	11.77
411	Elo Ratings		moxieman	29	14.20
265	Update in SQL			73	12.63
500	Enchanted Necklace		csfpython	2	18.20
277	The Adventure of Morse Code		zelevin	68	12.75
324	Merge Sort			54	13.14
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
193	Maximum Flow			87	12.33
166	Page Rank as Eigenvector			94	12.19
459	Number String Multiples of Thirteen		csfpython	13	15.52
488	Accurate Curve Fitting		csfpython	5	16.99
499	Binary Frog		csfpython	2	18.20
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	12.51
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
466	Dictionary Entries		csfpython	10	15.94
434	A Crime on Logic Island Advanced		csfpython	18	14.99
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
293	Sums of Triplets			48	13.34
175	Algae Robot			74	12.61
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
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
475	Medieval Medicine		zelevin	6	16.73
315	Count the Common Factors		csfpython	38	13.74
255	LCM of a range			50	13.28
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
147	Color Cubes Advanced			61	12.94
247	Towers of Hanoi			43	13.53
486	Two Colour Special Nim		csfpython	3	17.70
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	14.08
450	Bead Games		csfpython	8	16.29
270	Hexlife			35	13.88
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
465	Red Blue Hackenbush		csfpython	5	16.99
405	Three Friendly Knights		csfpython	13	15.52
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
353	Hurkle Hunter			19	14.90
243	Grille Encryption			33	13.98
290	Every Leaf on Every Tree		zelevin	27	14.32
455	D flip-flop			6	16.73
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
346	Long Decimal Fractions		csfpython	19	14.90
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
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
462	Rota Boards		csfpython	3	17.70
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
263	Easter Bunnies 3D		gardengnome	18	14.99
380	Treap Study			9	16.11
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