Home / Login
Problems
School
Ranking
Forum
Help
Mess
11:32:43
Problems
Note that you can solve most task in any order!
Already solved ones are at the bottom of the table.
Volume
:
Simple
Implementation
Popular Algos
Puzzles
Special
all tags
Trending
Sort by Num of Solvers
Sort by Creation Order
by Solvers (with solved)
by Creation (with solved)
Id
Title
Translations
Author
Solved
Blessing
1
Sum "A+B"
DE
ES
FR
AR
ZH
RO
RU
SK
53787
1.00
2
Sum in Loop
DE
ES
FR
AR
ZH
RO
RU
SK
33040
1.85
3
Sums in Loop
DE
ES
FR
AR
ZH
RO
RU
SK
25172
2.32
4
Minimum of Two
DE
ES
FR
AR
ZH
RO
RU
SK
21917
2.56
5
Minimum of Three
DE
ES
FR
AR
ZH
RO
RU
SK
19643
2.75
15
Maximum of array
DE
ES
AR
ZH
RO
RU
SK
17176
2.98
6
Rounding
DE
ES
AR
ZH
RO
RU
SK
15884
3.12
7
Fahrenheit to Celsius
DE
ES
AR
ZH
RO
RU
SK
15163
3.20
20
Vowel Count
DE
ES
AR
ZH
RO
RU
SK
12317
3.56
11
Sum of digits
DE
ES
RU
ZH
SK
12175
3.58
41
Median of Three
DE
ES
AR
ZH
RO
RU
SK
10531
3.83
8
Arithmetic Progression
DE
ES
RU
ZH
SK
11389
3.70
28
Body Mass Index
DE
ES
ZH
RU
SK
10369
3.86
9
Triangles
DE
ES
RU
ZH
SK
10814
3.79
13
Weighted sum of digits
DE
ES
RU
ZH
SK
9869
3.95
43
Dice Rolling
DE
ES
ZH
RU
SK
8934
4.12
16
Average of an array
DE
ES
RU
SK
9352
4.04
30
Reverse String
DE
RU
SK
8811
4.14
17
Array Checksum
DE
ES
RU
SK
8659
4.17
21
Array Counters
DE
ES
RU
SK
8096
4.29
48
Collatz Sequence
DE
ES
RU
SK
7041
4.53
10
Linear Function
DE
ES
RU
SK
7763
4.36
12
Modulo and time difference
DE
ES
RU
SK
7145
4.51
14
Modular Calculator
ES
SK
6598
4.64
27
Bubble Sort
ES
RU
SK
5982
4.82
26
Greatest Common Divisor
RU
SK
5836
4.86
18
Square Root
ES
RU
5585
4.93
29
Sort with Indexes
RU
5400
4.99
50
Palindromes
DE
ES
RU
SK
4938
5.15
23
Bubble in Array
ES
RU
5175
5.07
52
Pythagorean Theorem
RU
4732
5.22
31
Rotate String
ES
RU
4941
5.15
67
Fibonacci Sequence
RU
4292
5.39
68
Bicycle Race
ES
RU
4262
5.40
57
Smoothing the Weather
ES
RU
4297
5.39
24
Neumann's Random Generator
DE
ES
RU
4618
5.26
104
Triangle Area
3366
5.81
35
Savings Calculator
4046
5.49
25
Linear Congruential Generator
RU
4006
5.51
81
Bit Count
RU
3416
5.79
44
Double Dice Roll
RU
3794
5.61
32
Josephus Problem
RU
3896
5.56
128
Combinations Counting
2672
6.21
19
Matching Brackets
ES
RU
3631
5.68
58
Card Names
3241
5.88
47
Caesar Shift Cipher
SK
3327
5.83
49
Rock Paper Scissors
3273
5.86
55
Matching Words
3182
5.91
94
Fool's Day 2014
SK
2770
6.15
59
Bulls and Cows
2863
6.09
61
Prime Numbers Generation
RU
2819
6.12
22
Two Printers
ES
RU
3017
6.00
42
Blackjack Counting
2591
6.27
120
Selection Sort
2035
6.69
38
Quadratic Equation
2388
6.41
33
Parity Control
RU
2339
6.45
171
Tree Height Measurement
1448
7.28
53
King and Queen
2093
6.64
34
Binary Search
2155
6.59
69
Fibonacci Divisibility
1855
6.85
37
Mortgage Calculator
ZH
2022
6.70
45
Cards Shuffling
ZH
1965
6.75
63
Integer Factorization
ZH
1779
6.92
46
Tic-Tac-Toe
ZH
1825
6.88
72
Funny Words Generator
1591
7.11
62
Prime Ranges
1626
7.08
121
Insertion Sort
1344
7.41
172
Cloud Altitude Measurement
1083
7.78
127
Anagrams
1272
7.50
75
Yacht or Dice Poker
1504
7.21
134
Flying Text Screensaver
1177
7.64
39
Share Price Volatility
1504
7.21
156
Luhn Algorithm
SK
995
7.93
114
Tricky Printing
1119
7.73
406
Wormholes of Cygnus
moxieman
6
16.54
80
Duel Chances
1133
7.70
135
Variable Length Code
888
8.13
74
Clock Hands
1069
7.81
36
Code Guesser
UA
1165
7.66
105
Convex Polygon Area
915
8.08
54
Pythagorean Triples
1035
7.86
145
Modular Exponentiation
767
8.38
73
Hexagonal Grid
944
8.02
116
Summing Up
812
8.28
97
Girls and Pigs
844
8.22
405
Three Friendly Knights
csfpython
7
16.31
187
Static Web Page
583
8.86
385
Number of steps in Euclidean Algorithm
gardengnome
59
12.81
181
Reverse Polish Notation
584
8.85
188
Basics of HTML
557
8.94
399
Methane Identification
moxieman
21
14.55
122
QuickSort
680
8.59
98
Azimuth at Treasure Island
730
8.47
85
Rotation in 2D Space
735
8.46
51
Dungeons and Dragons Dice
UA
795
8.32
56
Life is Simple
769
8.38
377
Sum of Digits Divisibility
66
12.62
401
Methane Rotation
moxieman
14
15.22
70
Most Frequent Word
705
8.53
40
Paths in the Grid
UA
764
8.39
66
Caesar Cipher Cracker
706
8.53
88
Pitch and Notes
645
8.68
400
Memory Check
15
15.11
108
Star Medals
595
8.82
211
Information Entropy
366
9.66
95
Simple Linear Regression
581
8.86
87
Tree Builder
590
8.84
207
Suffix Array
364
9.67
60
Sweet Harvest
623
8.74
77
Point to Segment Distance
585
8.85
176
Say 100
399
9.51
86
Brainfuck Interpreter
551
8.95
143
Extended Euclidean Algorithm
434
9.37
195
Mul Two
346
9.76
71
Fibonacci Divisibility Advanced
546
8.97
91
Game of 2048
510
9.09
191
Spaceship Weight Fraud
342
9.78
119
Brain Fibo
454
9.29
101
Gradient Calculation
476
9.21
206
Base-32 Encoding
309
9.96
82
Levenshtein Distance
488
9.17
89
Instrument Tuner
455
9.29
403
Hi-Lo dice game
6
16.54
131
Four Pics One Word
386
9.57
64
Maze Pathfinder
473
9.22
189
Dynamic Web Page
300
10.01
79
Cycles Detection
436
9.36
92
Binary Heap
413
9.45
150
Introducing Regexps
328
9.85
126
Sequence of Squares
354
9.72
136
Variable Length Code Unpack
341
9.79
404
Methane Normalization
moxieman
4
17.13
366
Image Cutting
oezguery
51
13.06
170
Binary Search in Array
290
10.07
167
Copy Line
292
10.06
197
Loops in Assembly
255
10.29
83
Graph Generator
391
9.55
90
Lexicographic Permutations
376
9.62
301
Skyscraper Price
125
11.52
154
Breadth First Search
294
10.04
78
Bezier Curves
378
9.61
117
Divide by Two
321
9.89
99
Uphill Shooting
334
9.82
65
Transitive Closure on Candy States
362
9.68
144
Modular Inverse
272
10.18
374
Longest Common Subsequence
34
13.75
155
Depth First Search
258
10.27
174
Calculation of Pi
235
10.43
371
Pages to Print
36
13.65
407
River Labyrinth
-
19.92
161
Topological Sorting
242
10.38
133
Billiard Ball
260
10.26
165
Safe Landing
229
10.48
190
Query String Parameters
202
10.69
384
Equal Hamming Distance
csfpython
21
14.55
140
Proper Bracket Sequences
243
10.37
184
Matches Picking
quandray
200
10.71
323
Next Palindrome
csfpython
74
12.42
76
Pawn Move Validator
291
10.06
96
Snake Arcade
271
10.18
103
Easter Eggs
257
10.28
123
Knapsack of Integers
239
10.40
93
Starving Priority Queue
262
10.24
360
Whisky Blending
csfpython
39
13.51
402
Game of Stones
csfpython
4
17.13
130
Combinations with Repetitions
228
10.48
173
Chords of Music
192
10.78
84
Dijkstra in the Network
265
10.22
125
Bogosort
230
10.47
381
Finding Squares
csfpython
21
14.55
368
Number Base Palindrome
csfpython
31
13.90
337
Introducing Zeckendorf
csfpython
55
12.93
372
String Minimization
27
14.13
146
Color Cubes
198
10.73
109
Lucky Tickets
226
10.50
151
Word Ladders
190
10.80
389
Binary Split Guessing Game
csfpython
13
15.34
208
Neighborhood of a String
144
11.28
390
Card Pairing Solitaire
12
15.47
164
Page Rank
172
10.97
129
Enumerating Combinations
196
10.74
194
Convex Hull and Farmers
147
11.24
138
Huffman Coding
185
10.84
329
Roman Arithmetic
csfpython
53
12.99
364
Arthur Engel's Randomizer
29
14.01
139
Beam Balance and Masses
182
10.87
201
Point in Polygon
138
11.35
199
Employees Web App
139
11.34
393
Urban Planning
csfpython
9
15.92
359
Find 3 Numbers
csfpython
31
13.90
192
Gangster Battles
136
11.38
152
RSA Cryptography
161
11.08
137
Shannon-Fano Coding
168
11.01
388
Fibonacci Guessing Game
11
15.61
398
Collecting Diamonds
csfpython
5
16.81
111
Necklace Count
176
10.93
244
Introducing SQL
96
11.98
110
Lucky Tickets Advanced
166
11.03
168
Caesar meets BF
133
11.41
245
Aggregations in SQL
86
12.16
269
Fibonacci coding
73
12.45
202
Dancing Pairs
108
11.77
179
Look and Say binary
119
11.61
198
Prn Hex Str
109
11.76
162
Rubik's Cube
126
11.51
148
Public Key Cryptography Intro
133
11.41
214
Sick Travellers
98
11.94
124
Knapsack Backtracking
141
11.31
182
Frodo and Black Riders
112
11.71
392
Fixing an Anagram
7
16.31
386
Advent Calendar Chocolate
gardengnome
10
15.76
106
Random Search Optimization
149
11.22
253
Beautiful Line Chart
75
12.40
177
Nim Game
112
11.71
185
Simple 3D Scene
106
11.81
160
Social Web Scraper
117
11.64
294
Vigenere Cipher
52
13.03
395
Growth of Micro-Organisms
csfpython
5
16.81
102
Travelling Salesman
139
11.34
157
Emirp primE
113
11.70
158
Hamming Codes
111
11.73
258
Text Justification
65
12.64
246
Joins in SQL
70
12.52
291
Squirrels vs. Acorns
zelevin
49
13.13
159
Hard Life
103
11.85
379
Dice with Infinity Sides
telebashna
11
15.61
281
Basic Tokenizer
51
13.06
196
Fibonacci Randomizer
85
12.18
265
Update in SQL
57
12.87
277
The Adventure of Morse Code
zelevin
52
13.03
153
Fermat goes hacking RSA
99
11.92
351
Nicomachus
21
14.55
100
Crossing the Road
115
11.66
115
Gradient Descent for SLE
109
11.76
376
Cartesian Tree Visualization
11
15.61
186
Simple 3D Scene (cont)
82
12.25
335
Venus Visible
26
14.20
141
Sliding Window Search
97
11.96
397
Trading Bot
3
17.51
383
E2C2S - try harder!
gardengnome
8
16.11
394
Many Shortest Routes
csfpython
4
17.13
210
Ticket Puzzle
69
12.54
209
Suffix Array Advanced
69
12.54
166
Page Rank as Eigenvector
83
12.23
193
Maximum Flow
72
12.47
142
LZ77 decompression
89
12.11
203
Tic-Tac-Toe Minimax Algorithm
68
12.57
375
Space Invaders
10
15.76
219
Neural Network Calculation
61
12.75
112
Travelling Salesman Inverted
92
12.05
216
Cracking Linear Congruential Generator
59
12.81
363
Language Detector
13
15.34
382
Die Throw Sequences
csfpython
7
16.31
274
Two Buckets
40
13.47
113
Ground Zero
89
12.11
352
Hurkle
16
15.00
315
Count the Common Factors
csfpython
27
14.13
334
Find all of the SETs
csfpython
21
14.55
132
Stream Cipher Breaking
80
12.29
163
Colliding Balls
70
12.52
259
Easter Bunnies
gardengnome
42
13.39
175
Algae Robot
66
12.62
387
Big Numbers
csfpython
5
16.81
205
Clustering the Stars
56
12.90
200
Fizz Buzz in Asm
57
12.87
293
Sums of Triplets
31
13.90
354
Too Many Divisors
csfpython
14
15.22
353
Hurkle Hunter
14
15.22
107
Knight's Tour
81
12.27
230
Move-To-Front Transform
47
13.20
367
Roguelike 1d
10
15.76
204
Wandering Star
53
12.99
347
Unwanted Multiples
csfpython
15
15.11
212
BCD to Hex
50
13.09
292
Factorial Trailing Zeroes
29
14.01
241
Village Ways
42
13.39
330
Easter Bunnies Are Back
gardengnome
19
14.72
396
Chocolate Triangles and BF
moxieman
2
18.01
257
Missing Records in SQL
36
13.65
218
Rain Must Fall
DE
45
13.27
346
Long Decimal Fractions
csfpython
14
15.22
358
Mandelbrot Set
11
15.61
307
The Problem of Too Many Clues
zelevin
23
14.40
149
Prime Chains
60
12.78
391
Scout Proficiency Badges
csfpython
3
17.51
378
Space Invaders Automation
6
16.54
338
Throwing Easter Eggs
gardengnome
15
15.11
233
Language Study
39
13.51
349
Burrows
gardengnome
12
15.47
178
Maze of the Wumpus
49
13.13
362
Euclid, Manhattan and Chebyshev
9
15.92
357
Ulam's Prime Spiral
10
15.76
147
Color Cubes Advanced
55
12.93
324
Merge Sort
17
14.90
380
Treap Study
5
16.81
361
Rogue Mazes
9
15.92
331
Rotating Toy Display
csfpython
15
15.11
118
Maxit Single-Player
59
12.81
180
Simple Game of Sticks
46
13.23
223
Introducing Scheme
37
13.60
297
Collatz in the Range
21
14.55
299
Tree Visualizer
20
14.63
340
Zeckendorf Lite
csfpython
12
15.47
287
Palindrome Frog
csfpython
22
14.48
229
Burrows-Wheeler Transform
33
13.80
255
LCM of a range
28
14.07
339
Parking Lot
12
15.47
296
Tree Value
RU
csfpython
20
14.63
183
Connect Four
41
13.43
247
Towers of Hanoi
29
14.01
313
Seven Segment Decoder
16
15.00
312
The Shredder Conundrum
zelevin
16
15.00
298
Revoltle
zelevin
18
14.81
344
Throwing Easter Eggs Part 2
gardengnome
10
15.76
270
Hexlife
22
14.48
341
Zeckendorf Advanced
csfpython
10
15.76
261
Easter Bunnies 2D
gardengnome
23
14.40
284
Rotate Array In-Place
19
14.72
290
Every Leaf on Every Tree
zelevin
18
14.81
282
Predictable Board Game
csfpython
19
14.72
332
Easter Bunnies 2D Are Back
gardengnome
11
15.61
249
Turing Increment
24
14.33
217
Personality Swap
29
14.01
286
Self-Printing Program
18
14.81
238
Bear Hunt
25
14.26
234
Train Merge
25
14.26
326
Sum Them Forth
11
15.61
275
Three Buckets
18
14.81
268
Logic Transformation
19
14.72
169
Automated Landing
33
13.80
300
Run-Length Encoding
14
15.22
343
Village of Ticks
8
16.11
314
The Sorites Solution
zelevin
12
15.47
285
Rotate Matrix In Place
16
15.00
350
Colourful Egg Sequences
gardengnome
7
16.31
243
Grille Encryption
21
14.55
256
Rook Jump Maze
19
14.72
271
A Knight some Trolls and a Princess
csfpython
17
14.90
369
Flappy Bird
4
17.13
213
Micro-Life
SK
24
14.33
306
Line Drawing Algorithm
12
15.47
345
Elliptic Curves Basics
7
16.31
250
Turing Clone
19
14.72
336
Currency Arbitrage
8
16.11
333
Happy Triplets
8
16.11
289
The Case of the Desperate Mastermind
zelevin
13
15.34
220
Neural Network Training
21
14.55
365
Flower Border Arrangements
csfpython
4
17.13
260
Low Cost Road Network
csfpython
16
15.00
303
Towers Under Cover
11
15.61
373
Railroad Rat
csfpython
3
17.51
311
The Mirror Maze
zelevin
10
15.76
309
Board Game Sequences
csfpython
10
15.76
263
Easter Bunnies 3D
gardengnome
15
15.11
262
Easter Bunnies 2D Advanced
gardengnome
15
15.11
316
Apogee
9
15.92
288
Langton's Ant
csfpython
12
15.47
276
Lucky Pairs
csfpython
13
15.34
266
Pancake Sorting
14
15.22
370
Jewels
3
17.51
320
Accordion
pearlbarley
8
16.11
231
Dice Black Jack
17
14.90
319
Tower of Hanoi Rules
csfpython
8
16.11
279
Two Buckets Advanced
csfpython
12
15.47
328
Beep Beep Beep
7
16.31
254
Rule 30 by Turing
14
15.22
305
The Catacombs of Chronos
zelevin
9
15.92
325
Ultimate Sort Trial
7
16.31
221
XWords
quandray
17
14.90
355
Robots Game
4
17.13
322
Gray Decoder
7
16.31
310
Board Game Sequences Advanced
csfpython
8
16.11
222
Easter Eggs Advanced
16
15.00
342
Adaptive Arithmetic Coding
5
16.81
308
Circle Drawing Algorithm
8
16.11
295
Vigenere Cipher Cracker
9
15.92
235
Train Merge Advanced
14
15.22
304
Ordered Brackets
csfpython
8
16.11
242
Comment Stripper
13
15.34
356
Robots Game Autoplay
3
17.51
327
Dobbin's Long Journey
csfpython
5
16.81
215
Klotski
SK
13
15.34
267
Turing Maze
9
15.92
237
Road Network Destruction
11
15.61
264
Party Presents
csfpython
9
15.92
227
Hashtable Implementation
11
15.61
302
Sound-Controlled Robot
6
16.54
226
Multiplicative Persistence Backtrace
11
15.61
225
Hamurabi
11
15.61
283
Predictable Board Game on 10 Boards
csfpython
7
16.31
248
Christmas Puzzle
9
15.92
278
Polyomino Generation
7
16.31
224
Transposing List of Lists
10
15.76
252
Shadok and Gibis
8
16.11
317
Launch to Orbit
4
17.13
236
Is the Earth Flat
8
16.11
273
Logic Glitches
6
16.54
251
Radio Spies
7
16.31
348
Trick-Taking Game
2
18.01
321
Hanoi Tower Heights
csfpython
3
17.51
232
Shift Register Randomizer
7
16.31
272
Hexplore
5
16.81
240
Playfair Cipher Cracking
6
16.54
239
Foxes and Geese
6
16.54
280
Three Buckets Re-visited
csfpython
4
17.13
228
Maze Mapping Robot
5
16.81
318
Launch to Orbit automated
2
18.01