Crystal
Crystal
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Crystal Track Management

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

Students
2,275
Submissions
36,976
Mentoring Discussions
913

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.
21 concepts being taught
Ba
Basics
298 learnt
Bo
Bools
230 learnt
Nu
Numbers
188 learnt
Nu
Number Types
158 learnt
Cl
Classes
141 learnt
St
Strings
101 learnt
St
String Methods
82 learnt
Co
Conditionals
76 learnt
Re
Return
71 learnt
Wh
While Loops
71 learnt
Ra
Ranges
49 learnt
Ch
Char
56 learnt
Mo
Modules
47 learnt
Ni
Nil
56 learnt
Un
Union Type
46 learnt
Ca
Case
36 learnt
Ar
Array
34 learnt
Ar
Array Methods
32 learnt
Bi
Binary, Octal, and Hexadecimal
26 learnt
Bi
Bit Manipulation
24 learnt
Pr
Procs & Blocks
12 learnt
20 active learning exercises
Started
Attempts
Completions
Mentoring requests
Ary's Amazing Lasagna Ary's Amazing Lasagna
342
883 (avg. 2.6)
298 (87.1%)
2 (0.6%)
Crystal Hunter Crystal Hunter
244
646 (avg. 2.6)
230 (94.3%)
3 (1.2%)
Wellington's Weather Station Wellington's Weather Station
206
1,408 (avg. 6.8)
188 (91.3%)
2 (1.0%)
Navigation Computer Navigation Computer
163
518 (avg. 3.2)
158 (96.9%)
0 (0.0%)
Johannes' Juice Maker Johannes' Juice Maker
148
990 (avg. 6.7)
141 (95.3%)
3 (2.0%)
Party Robot Party Robot
104
530 (avg. 5.1)
101 (97.1%)
1 (1.0%)
High School Sweetheart High School Sweetheart
84
398 (avg. 4.7)
82 (97.6%)
1 (1.2%)
Meltdown Mitigation Meltdown Mitigation
79
354 (avg. 4.5)
76 (96.2%)
2 (2.5%)
Interest is Interesting Interest is Interesting
72
374 (avg. 5.2)
71 (98.6%)
1 (1.4%)
Chess Game Chess Game
51
368 (avg. 7.2)
49 (96.1%)
1 (2.0%)
Library of Luton Library of Luton
58
416 (avg. 7.2)
56 (96.6%)
1 (1.7%)
Bellebrook Basket League Bellebrook Basket League
49
416 (avg. 8.5)
47 (95.9%)
1 (2.0%)
Castle Dinner Castle Dinner
56
209 (avg. 3.7)
56 (100.0%)
1 (1.8%)
Password Lock Password Lock
46
470 (avg. 10.2)
46 (100.0%)
1 (2.2%)
Blackjack Blackjack
38
256 (avg. 6.7)
36 (94.7%)
0 (0.0%)
Language List Language List
34
113 (avg. 3.3)
34 (100.0%)
1 (2.9%)
Chaitanas Colossal Coaster Chaitanas Colossal Coaster
32
203 (avg. 6.3)
32 (100.0%)
1 (3.1%)
Foto Fusionist Foto Fusionist
29
110 (avg. 3.8)
26 (89.7%)
1 (3.4%)
Secrets Secrets
24
51 (avg. 2.1)
24 (100.0%)
1 (4.2%)
Task Handler Task Handler
12
51 (avg. 4.3)
12 (100.0%)
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: c310c52fe8a632b1cdbb97ba41fdf64f60c3b3c6 (Updates should be instant)

Next goal: Implement 130 practice exercises. Find out more.
105 active practice exercises
Started
Attempts
Completions
Mentoring requests
Hello World Hello World
1,746
2,156 (avg. 1.2)
1,500 (85.9%)
5 (0.3%)
Acronym Acronym
411
2,225 (avg. 5.4)
242 (58.9%)
17 (4.1%)
Anagram Anagram
266
1,215 (avg. 4.6)
211 (79.3%)
15 (5.6%)
Armstrong Numbers Armstrong Numbers
172
598 (avg. 3.5)
143 (83.1%)
7 (4.1%)
Atbash Cipher Atbash Cipher
193
1,505 (avg. 7.8)
146 (75.6%)
10 (5.2%)
Bob Bob
327
855 (avg. 2.6)
260 (79.5%)
72 (22.0%)
Collatz Conjecture Collatz Conjecture
94
375 (avg. 4.0)
75 (79.8%)
5 (5.3%)
Difference of Squares Difference of Squares
198
657 (avg. 3.3)
182 (91.9%)
38 (19.2%)
ETL ETL
65
153 (avg. 2.4)
53 (81.5%)
3 (4.6%)
Flatten Array Flatten Array
96
170 (avg. 1.8)
77 (80.2%)
5 (5.2%)
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
77
257 (avg. 3.3)
66 (85.7%)
6 (7.8%)
Leap Leap
295
649 (avg. 2.2)
274 (92.9%)
44 (14.9%)
Matching Brackets Matching Brackets
190
314 (avg. 1.7)
141 (74.2%)
19 (10.0%)
Pangram Pangram
213
490 (avg. 2.3)
189 (88.7%)
42 (19.7%)
Raindrops Raindrops
266
489 (avg. 1.8)
239 (89.8%)
63 (23.7%)
Resistor Color Resistor Color
61
137 (avg. 2.2)
53 (86.9%)
5 (8.2%)
Resistor Color Duo Resistor Color Duo
58
236 (avg. 4.1)
49 (84.5%)
5 (8.6%)
Reverse String Reverse String
95
162 (avg. 1.7)
85 (89.5%)
4 (4.2%)
Rotational Cipher Rotational Cipher
22
76 (avg. 3.5)
21 (95.5%)
1 (4.5%)
RNA Transcription RNA Transcription
312
583 (avg. 1.9)
285 (91.3%)
72 (23.1%)
Run-Length Encoding Run-Length Encoding
76
209 (avg. 2.8)
53 (69.7%)
4 (5.3%)
Scrabble Score Scrabble Score
57
169 (avg. 3.0)
47 (82.5%)
3 (5.3%)
Triangle Triangle
182
600 (avg. 3.3)
148 (81.3%)
46 (25.3%)
Darts Darts
48
141 (avg. 2.9)
41 (85.4%)
4 (8.3%)
Two Fer Two Fer
74
102 (avg. 1.4)
65 (87.8%)
5 (6.8%)
Resistor Color Trio Resistor Color Trio
22
355 (avg. 16.1)
17 (77.3%)
2 (9.1%)
Space Age Space Age
56
136 (avg. 2.4)
42 (75.0%)
2 (3.6%)
Resistor Color Expert Resistor Color Expert
12
97 (avg. 8.1)
9 (75.0%)
0 (0.0%)
ISBN Verifier ISBN Verifier
52
294 (avg. 5.7)
42 (80.8%)
1 (1.9%)
Luhn Luhn
61
365 (avg. 6.0)
41 (67.2%)
1 (1.6%)
Binary Search Binary Search
20
92 (avg. 4.6)
15 (75.0%)
0 (0.0%)
Phone Number Phone Number
18
179 (avg. 9.9)
14 (77.8%)
2 (11.1%)
Nucleotide Count Nucleotide Count
16
106 (avg. 6.6)
15 (93.8%)
2 (12.5%)
Roman Numerals Roman Numerals
125
233 (avg. 1.9)
94 (75.2%)
7 (5.6%)
High Scores High Scores
17
34 (avg. 2.0)
15 (88.2%)
1 (5.9%)
Perfect Numbers Perfect Numbers
57
96 (avg. 1.7)
44 (77.2%)
1 (1.8%)
Grains Grains
64
190 (avg. 3.0)
50 (78.1%)
3 (4.7%)
Secret Handshake Secret Handshake
47
85 (avg. 1.8)
32 (68.1%)
1 (2.1%)
Bottle Song Bottle Song
27
94 (avg. 3.5)
21 (77.8%)
0 (0.0%)
Clock Clock
84
638 (avg. 7.6)
70 (83.3%)
2 (2.4%)
All Your Base All Your Base
31
111 (avg. 3.6)
21 (67.7%)
1 (3.2%)
Largest Series Product Largest Series Product
136
384 (avg. 2.8)
112 (82.4%)
32 (23.5%)
Pascal's Triangle Pascal's Triangle
61
204 (avg. 3.3)
44 (72.1%)
1 (1.6%)
Sieve Sieve
130
202 (avg. 1.6)
99 (76.2%)
10 (7.7%)
Wordy Wordy
12
55 (avg. 4.6)
7 (58.3%)
0 (0.0%)
Saddle Points Saddle Points
7
8 (avg. 1.1)
5 (71.4%)
0 (0.0%)
Nth Prime Nth Prime
35
227 (avg. 6.5)
24 (68.6%)
2 (5.7%)
Prime Factors Prime Factors
31
64 (avg. 2.1)
23 (74.2%)
0 (0.0%)
Protein Translation Protein Translation
222
2,266 (avg. 10.2)
194 (87.4%)
8 (3.6%)
Series Series
40
176 (avg. 4.4)
31 (77.5%)
1 (2.5%)
Sublist Sublist
9
15 (avg. 1.7)
8 (88.9%)
0 (0.0%)
Word Count Word Count
14
82 (avg. 5.9)
12 (85.7%)
0 (0.0%)
Matrix Matrix
42
284 (avg. 6.8)
40 (95.2%)
0 (0.0%)
Queen Attack Queen Attack
14
27 (avg. 1.9)
11 (78.6%)
0 (0.0%)
Affine Cipher Affine Cipher
7
28 (avg. 4.0)
5 (71.4%)
1 (14.3%)
Kindergarten Garden Kindergarten Garden
6
27 (avg. 4.5)
5 (83.3%)
0 (0.0%)
Eliud's Eggs Eliud's Eggs
9
19 (avg. 2.1)
8 (88.9%)
0 (0.0%)
Proverb Proverb
44
62 (avg. 1.4)
34 (77.3%)
3 (6.8%)
Tournament Tournament
4
71 (avg. 17.8)
3 (75.0%)
0 (0.0%)
Circular Buffer Circular Buffer
48
585 (avg. 12.2)
43 (89.6%)
2 (4.2%)
Crypto Square Crypto Square
5
34 (avg. 6.8)
4 (80.0%)
0 (0.0%)
Transpose Transpose
6
78 (avg. 13.0)
3 (50.0%)
0 (0.0%)
Yacht Yacht
5
30 (avg. 6.0)
3 (60.0%)
0 (0.0%)
Spiral Matrix Spiral Matrix
5
42 (avg. 8.4)
4 (80.0%)
0 (0.0%)
Food Chain Food Chain
4
3 (avg. 0.8)
2 (50.0%)
0 (0.0%)
Robot Simulator Robot Simulator
16
51 (avg. 3.2)
15 (93.8%)
0 (0.0%)
Forth Forth
65
211 (avg. 3.2)
38 (58.5%)
7 (10.8%)
Grade School Grade School
5
20 (avg. 4.0)
5 (100.0%)
0 (0.0%)
Meetup Meetup
34
89 (avg. 2.6)
22 (64.7%)
1 (2.9%)
Killer Sudoku Helper Killer Sudoku Helper
5
23 (avg. 4.6)
4 (80.0%)
0 (0.0%)
Minesweeper Minesweeper
7
26 (avg. 3.7)
4 (57.1%)
0 (0.0%)
Strain Strain
42
55 (avg. 1.3)
29 (69.0%)
0 (0.0%)
Bank Account Bank Account
11
26 (avg. 2.4)
10 (90.9%)
0 (0.0%)
Palindrome Products Palindrome Products
10
40 (avg. 4.0)
7 (70.0%)
1 (10.0%)
Linked List Linked List
16
161 (avg. 10.1)
12 (75.0%)
0 (0.0%)
Allergies Allergies
47
148 (avg. 3.1)
36 (76.6%)
3 (6.4%)
Pig Latin Pig Latin
4
4 (avg. 1.0)
3 (75.0%)
0 (0.0%)
Diamond Diamond
6
16 (avg. 2.7)
6 (100.0%)
0 (0.0%)
Rail Fence Cipher Rail Fence Cipher
7
12 (avg. 1.7)
4 (57.1%)
0 (0.0%)
Rational Numbers Rational Numbers
6
15 (avg. 2.5)
3 (50.0%)
0 (0.0%)
Bowling Bowling
4
44 (avg. 11.0)
3 (75.0%)
0 (0.0%)
Knapsack Knapsack
5
5 (avg. 1.0)
4 (80.0%)
0 (0.0%)
Variable Length Quantity Variable Length Quantity
5
22 (avg. 4.4)
4 (80.0%)
0 (0.0%)
Rectangles Rectangles
3
8 (avg. 2.7)
2 (66.7%)
0 (0.0%)
Complex Numbers Complex Numbers
5
13 (avg. 2.6)
4 (80.0%)
0 (0.0%)
Word Search Word Search
4
27 (avg. 6.8)
3 (75.0%)
0 (0.0%)
Sum of Multiples Sum of Multiples
46
125 (avg. 2.7)
35 (76.1%)
0 (0.0%)
Pythagorean Triplet Pythagorean Triplet
8
17 (avg. 2.1)
6 (75.0%)
0 (0.0%)
State of Tic-Tac-Toe State of Tic-Tac-Toe
7
85 (avg. 12.1)
5 (71.4%)
1 (14.3%)
Change Change
6
21 (avg. 3.5)
5 (83.3%)
0 (0.0%)
Dominoes Dominoes
9
27 (avg. 3.0)
6 (66.7%)
0 (0.0%)
OCR Numbers OCR Numbers
5
26 (avg. 5.2)
4 (80.0%)
0 (0.0%)
Poker Poker
3
102 (avg. 34.0)
2 (66.7%)
0 (0.0%)
Connect Connect
5
17 (avg. 3.4)
3 (60.0%)
0 (0.0%)
React React
113
212 (avg. 1.9)
46 (40.7%)
5 (4.4%)
Say Say
4
9 (avg. 2.3)
2 (50.0%)
0 (0.0%)
Two Bucket Two Bucket
10
73 (avg. 7.3)
4 (40.0%)
0 (0.0%)
Binary Search Tree Binary Search Tree
151
1,197 (avg. 7.9)
79 (52.3%)
12 (7.9%)
Alphametics Alphametics
3
20 (avg. 6.7)
2 (66.7%)
0 (0.0%)
Simple Cipher Simple Cipher
44
461 (avg. 10.5)
36 (81.8%)
0 (0.0%)
Book Store Book Store
5
8 (avg. 1.6)
3 (60.0%)
0 (0.0%)
List Ops List Ops
11
26 (avg. 2.4)
6 (54.5%)
0 (0.0%)
D&D Character D&D Character
4
3 (avg. 0.8)
3 (75.0%)
0 (0.0%)
2 deprecated practice exercises
Started
Attempts
Completions
Mentoring requests
Binary Binary
139
555 (avg. 4.0)
111 (79.9%)
9 (6.5%)
Scale Generator Scale Generator
3
2 (avg. 0.7)
2 (66.7%)
0 (0.0%)
25 unimplemented practice exercises
Conway's Game of Life Conway's Game of Life
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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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Zebra Puzzle Zebra Puzzle
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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: 6df2462cc5064adc9d746d9be6bfe88301bbdfbf (Takes up to 10 mins to deploy)

Total Test Runner Runs
34,256
Test Run Pass Rate
34.0% (11644)
Test Run Fail Rate
30.0% (10260)
Test Run Error Rate
36.1% (12352)

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: 96bcff25cdcdcd770ea8a800b1d2de564b9f1a23 (Takes up to 10 mins to deploy)

Total Representer Runs
11,467
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: c8135d090a662e301280c67bd8915f8a2ebd4d33 (Takes up to 10 mins to deploy)

Total Analyzer Runs
10,444
Total Analysis Comments Made
9,796
Feedback Given Frequency
12.6%