Crystal Track Management

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

Students
2,319
Submissions
38,958
Mentoring Discussions
914

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
323 learnt
Bo
Bools
248 learnt
Nu
Numbers
205 learnt
Nu
Number Types
173 learnt
Cl
Classes
151 learnt
St
Strings
108 learnt
St
String Methods
90 learnt
Co
Conditionals
82 learnt
Re
Return
77 learnt
Wh
While Loops
77 learnt
Ra
Ranges
52 learnt
Ch
Char
61 learnt
Mo
Modules
51 learnt
Ni
Nil
62 learnt
Un
Union Type
49 learnt
Ca
Case
40 learnt
Ar
Array
37 learnt
Ar
Array Methods
35 learnt
Bi
Binary, Octal, and Hexadecimal
29 learnt
Bi
Bit Manipulation
26 learnt
Pr
Procs & Blocks
14 learnt
20 active learning exercises
Started
Attempts
Completions
Mentoring requests
Ary's Amazing Lasagna Ary's Amazing Lasagna
371
975 (avg. 2.6)
323 (87.1%)
2 (0.5%)
Crystal Hunter Crystal Hunter
264
699 (avg. 2.6)
248 (93.9%)
3 (1.1%)
Wellington's Weather Station Wellington's Weather Station
222
1,560 (avg. 7.0)
205 (92.3%)
2 (0.9%)
Navigation Computer Navigation Computer
178
610 (avg. 3.4)
173 (97.2%)
0 (0.0%)
Johannes' Juice Maker Johannes' Juice Maker
158
1,078 (avg. 6.8)
151 (95.6%)
3 (1.9%)
Party Robot Party Robot
113
566 (avg. 5.0)
108 (95.6%)
1 (0.9%)
High School Sweetheart High School Sweetheart
91
416 (avg. 4.6)
90 (98.9%)
1 (1.1%)
Meltdown Mitigation Meltdown Mitigation
86
405 (avg. 4.7)
82 (95.3%)
2 (2.3%)
Interest is Interesting Interest is Interesting
79
403 (avg. 5.1)
77 (97.5%)
1 (1.3%)
Chess Game Chess Game
54
380 (avg. 7.0)
52 (96.3%)
1 (1.9%)
Library of Luton Library of Luton
64
433 (avg. 6.8)
61 (95.3%)
1 (1.6%)
Bellebrook Basket League Bellebrook Basket League
54
438 (avg. 8.1)
51 (94.4%)
1 (1.9%)
Castle Dinner Castle Dinner
62
223 (avg. 3.6)
62 (100.0%)
1 (1.6%)
Password Lock Password Lock
49
481 (avg. 9.8)
49 (100.0%)
1 (2.0%)
Blackjack Blackjack
42
265 (avg. 6.3)
40 (95.2%)
0 (0.0%)
Language List Language List
37
134 (avg. 3.6)
37 (100.0%)
1 (2.7%)
Chaitanas Colossal Coaster Chaitanas Colossal Coaster
35
217 (avg. 6.2)
35 (100.0%)
1 (2.9%)
Foto Fusionist Foto Fusionist
31
120 (avg. 3.9)
29 (93.5%)
1 (3.2%)
Secrets Secrets
26
57 (avg. 2.2)
26 (100.0%)
1 (3.8%)
Task Handler Task Handler
14
61 (avg. 4.4)
14 (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: 716f580f6e583007444a447217ed9cb8e039e6a3 (Updates should be instant)

Next goal: Implement 130 practice exercises. Find out more.
106 active practice exercises
Started
Attempts
Completions
Mentoring requests
Hello World Hello World
1,798
2,217 (avg. 1.2)
1,538 (85.5%)
5 (0.3%)
Acronym Acronym
411
2,225 (avg. 5.4)
242 (58.9%)
17 (4.1%)
Anagram Anagram
268
1,247 (avg. 4.7)
212 (79.1%)
15 (5.6%)
Armstrong Numbers Armstrong Numbers
174
602 (avg. 3.5)
144 (82.8%)
7 (4.0%)
Atbash Cipher Atbash Cipher
194
1,522 (avg. 7.8)
146 (75.3%)
10 (5.2%)
Bob Bob
328
888 (avg. 2.7)
260 (79.3%)
72 (22.0%)
Collatz Conjecture Collatz Conjecture
95
412 (avg. 4.3)
75 (78.9%)
5 (5.3%)
Difference of Squares Difference of Squares
199
658 (avg. 3.3)
183 (92.0%)
38 (19.1%)
ETL ETL
65
153 (avg. 2.4)
53 (81.5%)
3 (4.6%)
Flatten Array Flatten Array
97
171 (avg. 1.8)
78 (80.4%)
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
301
674 (avg. 2.2)
280 (93.0%)
44 (14.6%)
Matching Brackets Matching Brackets
191
318 (avg. 1.7)
141 (73.8%)
19 (9.9%)
Pangram Pangram
222
541 (avg. 2.4)
197 (88.7%)
42 (18.9%)
Raindrops Raindrops
268
501 (avg. 1.9)
241 (89.9%)
63 (23.5%)
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
96
164 (avg. 1.7)
86 (89.6%)
4 (4.2%)
Rotational Cipher Rotational Cipher
22
76 (avg. 3.5)
21 (95.5%)
1 (4.5%)
RNA Transcription RNA Transcription
313
585 (avg. 1.9)
286 (91.4%)
72 (23.0%)
Run-Length Encoding Run-Length Encoding
77
209 (avg. 2.7)
53 (68.8%)
4 (5.2%)
Scrabble Score Scrabble Score
58
170 (avg. 2.9)
48 (82.8%)
3 (5.2%)
Triangle Triangle
184
613 (avg. 3.3)
150 (81.5%)
46 (25.0%)
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
59
145 (avg. 2.5)
44 (74.6%)
3 (5.1%)
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
367 (avg. 6.0)
41 (67.2%)
1 (1.6%)
Binary Search Binary Search
21
118 (avg. 5.6)
16 (76.2%)
0 (0.0%)
Phone Number Phone Number
19
201 (avg. 10.6)
15 (78.9%)
2 (10.5%)
Nucleotide Count Nucleotide Count
17
117 (avg. 6.9)
16 (94.1%)
2 (11.8%)
Roman Numerals Roman Numerals
127
254 (avg. 2.0)
95 (74.8%)
7 (5.5%)
High Scores High Scores
19
45 (avg. 2.4)
17 (89.5%)
1 (5.3%)
Perfect Numbers Perfect Numbers
58
110 (avg. 1.9)
45 (77.6%)
1 (1.7%)
Grains Grains
66
208 (avg. 3.2)
52 (78.8%)
3 (4.5%)
Secret Handshake Secret Handshake
49
99 (avg. 2.0)
33 (67.3%)
1 (2.0%)
Bottle Song Bottle Song
28
112 (avg. 4.0)
22 (78.6%)
0 (0.0%)
Clock Clock
86
657 (avg. 7.6)
72 (83.7%)
2 (2.3%)
All Your Base All Your Base
33
126 (avg. 3.8)
22 (66.7%)
1 (3.0%)
Largest Series Product Largest Series Product
137
398 (avg. 2.9)
113 (82.5%)
32 (23.4%)
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
227
2,348 (avg. 10.3)
199 (87.7%)
8 (3.5%)
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
43
285 (avg. 6.6)
41 (95.3%)
0 (0.0%)
Queen Attack Queen Attack
16
31 (avg. 1.9)
13 (81.3%)
0 (0.0%)
Affine Cipher Affine Cipher
7
28 (avg. 4.0)
5 (71.4%)
1 (14.3%)
Kindergarten Garden Kindergarten Garden
7
28 (avg. 4.0)
6 (85.7%)
0 (0.0%)
Eliud's Eggs Eliud's Eggs
11
23 (avg. 2.1)
11 (100.0%)
0 (0.0%)
Proverb Proverb
44
62 (avg. 1.4)
34 (77.3%)
3 (6.8%)
Tournament Tournament
5
75 (avg. 15.0)
4 (80.0%)
0 (0.0%)
Circular Buffer Circular Buffer
51
589 (avg. 11.5)
46 (90.2%)
2 (3.9%)
Crypto Square Crypto Square
7
39 (avg. 5.6)
6 (85.7%)
0 (0.0%)
Transpose Transpose
7
80 (avg. 11.4)
4 (57.1%)
0 (0.0%)
Yacht Yacht
6
36 (avg. 6.0)
4 (66.7%)
0 (0.0%)
Spiral Matrix Spiral Matrix
6
46 (avg. 7.7)
5 (83.3%)
0 (0.0%)
Food Chain Food Chain
5
6 (avg. 1.2)
3 (60.0%)
0 (0.0%)
Robot Simulator Robot Simulator
17
53 (avg. 3.1)
16 (94.1%)
0 (0.0%)
Forth Forth
65
211 (avg. 3.2)
38 (58.5%)
7 (10.8%)
Grade School Grade School
6
23 (avg. 3.8)
6 (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
43
465 (avg. 10.8)
32 (74.4%)
0 (0.0%)
Strain Strain
42
55 (avg. 1.3)
29 (69.0%)
0 (0.0%)
Bank Account Bank Account
15
40 (avg. 2.7)
14 (93.3%)
0 (0.0%)
Palindrome Products Palindrome Products
10
40 (avg. 4.0)
7 (70.0%)
1 (10.0%)
Linked List Linked List
18
165 (avg. 9.2)
13 (72.2%)
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
7
16 (avg. 2.3)
4 (57.1%)
0 (0.0%)
Bowling Bowling
6
47 (avg. 7.8)
4 (66.7%)
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
7
15 (avg. 2.1)
5 (71.4%)
0 (0.0%)
Word Search Word Search
4
27 (avg. 6.8)
3 (75.0%)
0 (0.0%)
Sum of Multiples Sum of Multiples
48
129 (avg. 2.7)
37 (77.1%)
0 (0.0%)
Pythagorean Triplet Pythagorean Triplet
9
19 (avg. 2.1)
7 (77.8%)
0 (0.0%)
State of Tic-Tac-Toe State of Tic-Tac-Toe
9
88 (avg. 9.8)
7 (77.8%)
1 (11.1%)
Change Change
8
22 (avg. 2.8)
6 (75.0%)
0 (0.0%)
Dominoes Dominoes
11
28 (avg. 2.5)
7 (63.6%)
1 (9.1%)
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
213 (avg. 1.9)
46 (40.7%)
5 (4.4%)
Say Say
5
9 (avg. 1.8)
2 (40.0%)
0 (0.0%)
Two Bucket Two Bucket
12
158 (avg. 13.2)
6 (50.0%)
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
13
29 (avg. 2.2)
7 (53.8%)
0 (0.0%)
D&D Character D&D Character
6
20 (avg. 3.3)
5 (83.3%)
0 (0.0%)
Zebra Puzzle Zebra Puzzle
4
10 (avg. 2.5)
2 (50.0%)
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%)
24 unimplemented practice exercises
Conway's Game of Life Conway's Game of Life
Custom Set Custom Set
DOT DSL DOT DSL
Error Handling Error Handling
Go Counting Go Counting
Grep Grep
Hangman Hangman
House House
Ledger Ledger
Lens Person Lens Person
Markdown Markdown
Micro Blog Micro Blog
PaaS I/O PaaS I/O
Parallel Letter Frequency Parallel Letter Frequency
POV POV
REST API REST API
Robot Name Robot Name
Satellite Satellite
SGF Parsing SGF Parsing
Simple Linked List Simple Linked List
Square Root Square Root
Tree Building Tree Building
Twelve Days Twelve Days
Zipper Zipper

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: d939126f74c27c49bbcb93d29574a75a822a4205 (Takes up to 10 mins to deploy)

Total Test Runner Runs
36,229
Test Run Pass Rate
33.6% (12180)
Test Run Fail Rate
30.3% (10992)
Test Run Error Rate
36.0% (13057)

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: 50ff2d24bdcb2f8478831bfd7eafb9aa3515888e (Takes up to 10 mins to deploy)

Total Representer Runs
11,953
Total Representation Comments Made
0
Feedback Given Frequency
0.0%

Analyzer

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

Current version: e2e047f2d8ba25bc34024e35504cc7a918d2a2a3 (Takes up to 10 mins to deploy)

Total Analyzer Runs
10,929
Total Analysis Comments Made
10,372
Feedback Given Frequency
12.5%