Crystal
Crystal
About CrystalLearnPractice

Crystal Track Management

This page provides the Exercism community with the information and tools needed to manage the Crystal track.

Students
2,376
Submissions
41,342
Mentoring Discussions
916

The Crystal track needs attention ⚠️

Building

Crystal syllabus

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Help create the track syllabus: is a set of concepts and learning exercises put together to teach foundational elements of the programming language.

Next goal: Create a complete syllabus with at least 30 concepts. Find out more.
22 concepts being taught
Ba
Basics
345 learnt
Bo
Bools
263 learnt
Nu
Numbers
217 learnt
Nu
Number Types
182 learnt
Cl
Classes
159 learnt
St
Strings
117 learnt
St
String Methods
100 learnt
Co
Conditionals
89 learnt
Re
Return
82 learnt
Wh
While Loops
82 learnt
Ra
Ranges
54 learnt
Ch
Char
66 learnt
Mo
Modules
56 learnt
Ni
Nil
66 learnt
Un
Union Type
52 learnt
Ca
Case
41 learnt
Ar
Array
38 learnt
Ar
Array Methods
36 learnt
Bi
Binary, Octal, and Hexadecimal
34 learnt
Bi
Bit Manipulation
31 learnt
Pr
Procs & Blocks
16 learnt
It
Iteration
0 learnt
21 active learning exercises
Started
Attempts
Completions
Mentoring requests
Ary's Amazing Lasagna Ary's Amazing Lasagna
402
1,198 (avg. 3.0)
345 (85.8%)
2 (0.5%)
Crystal Hunter Crystal Hunter
280
728 (avg. 2.6)
263 (93.9%)
3 (1.1%)
Wellington's Weather Station Wellington's Weather Station
235
1,674 (avg. 7.1)
217 (92.3%)
2 (0.9%)
Navigation Computer Navigation Computer
187
651 (avg. 3.5)
182 (97.3%)
0 (0.0%)
Johannes' Juice Maker Johannes' Juice Maker
166
1,181 (avg. 7.1)
159 (95.8%)
3 (1.8%)
Party Robot Party Robot
121
717 (avg. 5.9)
117 (96.7%)
1 (0.8%)
High School Sweetheart High School Sweetheart
101
554 (avg. 5.5)
100 (99.0%)
1 (1.0%)
Meltdown Mitigation Meltdown Mitigation
94
508 (avg. 5.4)
89 (94.7%)
2 (2.1%)
Interest is Interesting Interest is Interesting
84
482 (avg. 5.7)
82 (97.6%)
1 (1.2%)
Chess Game Chess Game
56
395 (avg. 7.1)
54 (96.4%)
1 (1.8%)
Library of Luton Library of Luton
69
561 (avg. 8.1)
66 (95.7%)
1 (1.4%)
Bellebrook Basket League Bellebrook Basket League
59
534 (avg. 9.1)
56 (94.9%)
1 (1.7%)
Castle Dinner Castle Dinner
66
266 (avg. 4.0)
66 (100.0%)
1 (1.5%)
Password Lock Password Lock
52
568 (avg. 10.9)
52 (100.0%)
1 (1.9%)
Blackjack Blackjack
45
276 (avg. 6.1)
41 (91.1%)
0 (0.0%)
Language List Language List
39
140 (avg. 3.6)
38 (97.4%)
1 (2.6%)
Chaitanas Colossal Coaster Chaitanas Colossal Coaster
37
218 (avg. 5.9)
36 (97.3%)
1 (2.7%)
Foto Fusionist Foto Fusionist
36
163 (avg. 4.5)
34 (94.4%)
1 (2.8%)
Secrets Secrets
32
76 (avg. 2.4)
31 (96.9%)
1 (3.1%)
Task Handler Task Handler
17
87 (avg. 5.1)
16 (94.1%)
0 (0.0%)
spellbound-steel spellbound-steel
0
0 (avg. 0.0)
0 (0.0%)
0 (0.0%)

Practice Exercises

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Practice Exercises are exercises designed to allow students to solve an arbitrary problem, with the aim of them making use of the concepts they have learned so far.

Synced primary repo: c15a60c054c5deae3ec532e3a66b4d18cffcaf91 (Updates should be instant)

Next goal: Implement 130 practice exercises. Find out more.
107 active practice exercises
Started
Attempts
Completions
Mentoring requests
Hello World Hello World
1,868
2,294 (avg. 1.2)
1,586 (84.9%)
5 (0.3%)
Acronym Acronym
413
2,230 (avg. 5.4)
243 (58.8%)
17 (4.1%)
Anagram Anagram
273
1,249 (avg. 4.6)
214 (78.4%)
15 (5.5%)
Armstrong Numbers Armstrong Numbers
177
654 (avg. 3.7)
146 (82.5%)
7 (4.0%)
Atbash Cipher Atbash Cipher
196
1,526 (avg. 7.8)
146 (74.5%)
10 (5.1%)
Bob Bob
331
899 (avg. 2.7)
261 (78.9%)
72 (21.8%)
Collatz Conjecture Collatz Conjecture
97
413 (avg. 4.3)
76 (78.4%)
5 (5.2%)
Difference of Squares Difference of Squares
204
678 (avg. 3.3)
184 (90.2%)
38 (18.6%)
ETL ETL
67
157 (avg. 2.3)
53 (79.1%)
3 (4.5%)
Flatten Array Flatten Array
98
171 (avg. 1.7)
78 (79.6%)
5 (5.1%)
Gigasecond Gigasecond
359
630 (avg. 1.8)
323 (90.0%)
89 (24.8%)
Hamming Hamming
556
979 (avg. 1.8)
418 (75.2%)
187 (33.6%)
Isogram Isogram
78
257 (avg. 3.3)
66 (84.6%)
6 (7.7%)
Leap Leap
309
710 (avg. 2.3)
287 (92.9%)
44 (14.2%)
Matching Brackets Matching Brackets
193
325 (avg. 1.7)
142 (73.6%)
19 (9.8%)
Pangram Pangram
226
590 (avg. 2.6)
200 (88.5%)
42 (18.6%)
Raindrops Raindrops
269
501 (avg. 1.9)
241 (89.6%)
63 (23.4%)
Resistor Color Resistor Color
62
137 (avg. 2.2)
53 (85.5%)
5 (8.1%)
Resistor Color Duo Resistor Color Duo
59
236 (avg. 4.0)
49 (83.1%)
5 (8.5%)
Reverse String Reverse String
98
165 (avg. 1.7)
87 (88.8%)
4 (4.1%)
Rotational Cipher Rotational Cipher
23
76 (avg. 3.3)
21 (91.3%)
1 (4.3%)
RNA Transcription RNA Transcription
316
611 (avg. 1.9)
289 (91.5%)
72 (22.8%)
Run-Length Encoding Run-Length Encoding
78
209 (avg. 2.7)
53 (67.9%)
4 (5.1%)
Scrabble Score Scrabble Score
59
170 (avg. 2.9)
48 (81.4%)
3 (5.1%)
Triangle Triangle
188
660 (avg. 3.5)
152 (80.9%)
47 (25.0%)
Darts Darts
50
145 (avg. 2.9)
42 (84.0%)
4 (8.0%)
Two Fer Two Fer
76
102 (avg. 1.3)
65 (85.5%)
5 (6.6%)
Resistor Color Trio Resistor Color Trio
23
355 (avg. 15.4)
17 (73.9%)
2 (8.7%)
Space Age Space Age
60
145 (avg. 2.4)
44 (73.3%)
3 (5.0%)
Resistor Color Expert Resistor Color Expert
14
98 (avg. 7.0)
9 (64.3%)
0 (0.0%)
ISBN Verifier ISBN Verifier
53
294 (avg. 5.5)
42 (79.2%)
1 (1.9%)
Luhn Luhn
65
418 (avg. 6.4)
44 (67.7%)
2 (3.1%)
Binary Search Binary Search
24
131 (avg. 5.5)
18 (75.0%)
0 (0.0%)
Phone Number Phone Number
20
201 (avg. 10.1)
15 (75.0%)
2 (10.0%)
Nucleotide Count Nucleotide Count
18
117 (avg. 6.5)
16 (88.9%)
2 (11.1%)
Roman Numerals Roman Numerals
128
254 (avg. 2.0)
95 (74.2%)
7 (5.5%)
High Scores High Scores
21
45 (avg. 2.1)
17 (81.0%)
1 (4.8%)
Perfect Numbers Perfect Numbers
59
110 (avg. 1.9)
45 (76.3%)
1 (1.7%)
Grains Grains
67
208 (avg. 3.1)
52 (77.6%)
3 (4.5%)
Secret Handshake Secret Handshake
51
101 (avg. 2.0)
35 (68.6%)
1 (2.0%)
Bottle Song Bottle Song
30
135 (avg. 4.5)
23 (76.7%)
0 (0.0%)
Clock Clock
87
657 (avg. 7.6)
72 (82.8%)
2 (2.3%)
All Your Base All Your Base
34
153 (avg. 4.5)
23 (67.6%)
1 (2.9%)
Largest Series Product Largest Series Product
138
402 (avg. 2.9)
113 (81.9%)
32 (23.2%)
Pascal's Triangle Pascal's Triangle
63
235 (avg. 3.7)
44 (69.8%)
1 (1.6%)
Sieve Sieve
131
202 (avg. 1.5)
99 (75.6%)
10 (7.6%)
Wordy Wordy
14
139 (avg. 9.9)
8 (57.1%)
0 (0.0%)
Saddle Points Saddle Points
9
9 (avg. 1.0)
6 (66.7%)
0 (0.0%)
Nth Prime Nth Prime
37
233 (avg. 6.3)
25 (67.6%)
2 (5.4%)
Prime Factors Prime Factors
33
65 (avg. 2.0)
23 (69.7%)
0 (0.0%)
Protein Translation Protein Translation
236
2,437 (avg. 10.3)
206 (87.3%)
8 (3.4%)
Series Series
41
176 (avg. 4.3)
31 (75.6%)
1 (2.4%)
Sublist Sublist
12
23 (avg. 1.9)
10 (83.3%)
0 (0.0%)
Word Count Word Count
16
114 (avg. 7.1)
14 (87.5%)
1 (6.3%)
Matrix Matrix
45
286 (avg. 6.4)
42 (93.3%)
0 (0.0%)
Queen Attack Queen Attack
17
31 (avg. 1.8)
13 (76.5%)
0 (0.0%)
Affine Cipher Affine Cipher
8
28 (avg. 3.5)
5 (62.5%)
1 (12.5%)
Kindergarten Garden Kindergarten Garden
8
28 (avg. 3.5)
6 (75.0%)
0 (0.0%)
Eliud's Eggs Eliud's Eggs
13
34 (avg. 2.6)
12 (92.3%)
0 (0.0%)
Proverb Proverb
45
62 (avg. 1.4)
34 (75.6%)
3 (6.7%)
Tournament Tournament
6
75 (avg. 12.5)
4 (66.7%)
0 (0.0%)
Circular Buffer Circular Buffer
52
589 (avg. 11.3)
46 (88.5%)
2 (3.8%)
Crypto Square Crypto Square
8
39 (avg. 4.9)
6 (75.0%)
0 (0.0%)
Transpose Transpose
9
83 (avg. 9.2)
5 (55.6%)
0 (0.0%)
Yacht Yacht
8
43 (avg. 5.4)
5 (62.5%)
0 (0.0%)
Spiral Matrix Spiral Matrix
8
50 (avg. 6.3)
6 (75.0%)
0 (0.0%)
Food Chain Food Chain
6
6 (avg. 1.0)
3 (50.0%)
0 (0.0%)
Robot Simulator Robot Simulator
18
53 (avg. 2.9)
16 (88.9%)
0 (0.0%)
Forth Forth
66
211 (avg. 3.2)
38 (57.6%)
7 (10.6%)
Grade School Grade School
7
23 (avg. 3.3)
6 (85.7%)
0 (0.0%)
Meetup Meetup
35
89 (avg. 2.5)
22 (62.9%)
1 (2.9%)
Killer Sudoku Helper Killer Sudoku Helper
6
23 (avg. 3.8)
4 (66.7%)
0 (0.0%)
Minesweeper Minesweeper
59
582 (avg. 9.9)
45 (76.3%)
0 (0.0%)
Strain Strain
43
55 (avg. 1.3)
29 (67.4%)
0 (0.0%)
Bank Account Bank Account
18
44 (avg. 2.4)
15 (83.3%)
0 (0.0%)
Palindrome Products Palindrome Products
11
40 (avg. 3.6)
7 (63.6%)
1 (9.1%)
Linked List Linked List
19
165 (avg. 8.7)
13 (68.4%)
0 (0.0%)
Allergies Allergies
48
148 (avg. 3.1)
36 (75.0%)
3 (6.3%)
Pig Latin Pig Latin
6
9 (avg. 1.5)
4 (66.7%)
0 (0.0%)
Diamond Diamond
8
24 (avg. 3.0)
6 (75.0%)
0 (0.0%)
Rail Fence Cipher Rail Fence Cipher
8
12 (avg. 1.5)
4 (50.0%)
0 (0.0%)
Rational Numbers Rational Numbers
9
17 (avg. 1.9)
5 (55.6%)
0 (0.0%)
Bowling Bowling
7
47 (avg. 6.7)
4 (57.1%)
0 (0.0%)
Knapsack Knapsack
7
7 (avg. 1.0)
5 (71.4%)
0 (0.0%)
Variable Length Quantity Variable Length Quantity
7
22 (avg. 3.1)
4 (57.1%)
0 (0.0%)
Rectangles Rectangles
4
8 (avg. 2.0)
2 (50.0%)
0 (0.0%)
Complex Numbers Complex Numbers
9
17 (avg. 1.9)
6 (66.7%)
0 (0.0%)
Word Search Word Search
6
30 (avg. 5.0)
4 (66.7%)
0 (0.0%)
Sum of Multiples Sum of Multiples
49
129 (avg. 2.6)
37 (75.5%)
0 (0.0%)
Pythagorean Triplet Pythagorean Triplet
10
19 (avg. 1.9)
7 (70.0%)
0 (0.0%)
State of Tic-Tac-Toe State of Tic-Tac-Toe
12
90 (avg. 7.5)
8 (66.7%)
1 (8.3%)
Change Change
9
22 (avg. 2.4)
6 (66.7%)
0 (0.0%)
Dominoes Dominoes
12
28 (avg. 2.3)
7 (58.3%)
1 (8.3%)
OCR Numbers OCR Numbers
7
30 (avg. 4.3)
5 (71.4%)
0 (0.0%)
Conway's Game of Life Conway's Game of Life
5
5 (avg. 1.0)
2 (40.0%)
0 (0.0%)
Poker Poker
5
105 (avg. 21.0)
3 (60.0%)
0 (0.0%)
Connect Connect
7
21 (avg. 3.0)
4 (57.1%)
0 (0.0%)
React React
115
217 (avg. 1.9)
47 (40.9%)
6 (5.2%)
Say Say
6
10 (avg. 1.7)
3 (50.0%)
0 (0.0%)
Two Bucket Two Bucket
15
158 (avg. 10.5)
6 (40.0%)
0 (0.0%)
Binary Search Tree Binary Search Tree
152
1,197 (avg. 7.9)
79 (52.0%)
12 (7.9%)
Alphametics Alphametics
4
20 (avg. 5.0)
2 (50.0%)
0 (0.0%)
Simple Cipher Simple Cipher
46
461 (avg. 10.0)
36 (78.3%)
0 (0.0%)
Book Store Book Store
6
8 (avg. 1.3)
3 (50.0%)
0 (0.0%)
List Ops List Ops
14
29 (avg. 2.1)
7 (50.0%)
0 (0.0%)
D&D Character D&D Character
7
20 (avg. 2.9)
5 (71.4%)
0 (0.0%)
Zebra Puzzle Zebra Puzzle
7
23 (avg. 3.3)
4 (57.1%)
0 (0.0%)
2 deprecated practice exercises
Started
Attempts
Completions
Mentoring requests
Binary Binary
139
560 (avg. 4.0)
112 (80.6%)
10 (7.2%)
Scale Generator Scale Generator
3
2 (avg. 0.7)
2 (66.7%)
0 (0.0%)
23 unimplemented practice exercises
Custom Set Custom Set
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DOT DSL DOT DSL
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Error Handling Error Handling
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Go Counting Go Counting
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Grep Grep
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Hangman Hangman
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House House
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Ledger Ledger
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Lens Person Lens Person
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Markdown Markdown
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Micro Blog Micro Blog
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PaaS I/O PaaS I/O
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Parallel Letter Frequency Parallel Letter Frequency
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POV POV
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REST API REST API
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Robot Name Robot Name
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Satellite Satellite
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SGF Parsing SGF Parsing
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Simple Linked List Simple Linked List
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Square Root Square Root
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Tree Building Tree Building
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Twelve Days Twelve Days
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Zipper Zipper
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Programming Tags

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Help manage the tags used to group, filter and recommend solutions, approaches and articles.

0 tags

Test Runner

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Create Test Runners that have the single responsibility of taking a solution, running all tests and returning a standardized output.

Current version: c75884c9683fcb82c1aee5818c7b6760af4725cf (Takes up to 10 mins to deploy)

Total Test Runner Runs
38,599
Test Run Pass Rate
32.7% (12610)
Test Run Fail Rate
31.3% (12097)
Test Run Error Rate
36.0% (13892)

Representer

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Build a Representer: a bit of code that has the single responsibility of taking a solution and returning a normalized representation of it.

Current version: 8399b377591f4da3ad6b57658c30a302b687933d (Takes up to 10 mins to deploy)

Total Representer Runs
12,336
Total Representation Comments Made
0
Feedback Given Frequency
0.0%

Analyzer

Learn More

Build an Analyzer for Crystal: Exercism's analyzers automatically assess student's submissions and provide mentor-style commentary.

Current version: 466617a878e7d447960fc53b48751127c5e0f467 (Takes up to 10 mins to deploy)

Total Analyzer Runs
11,311
Total Analysis Comments Made
10,952
Feedback Given Frequency
12.3%