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Exercises

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66,971
students have developed their C skills on Exercism.

Students

66,971

Submissions

476,337

Mentoring Discussions

6,511

The C track needs attention ⚠️

Building

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Build Test Runners

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

Usage statistics

Total Test Runner Runs

433,956

Test Run Pass Rate

12.3% (53424)

Test Run Fail Rate

19.0% (82444)

Test Run Error Rate

68.7% (298088)

Build Analyzers

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

Next goal: Build an Analyzer. Find out more.

Build Representers

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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.

Next goal: Build a Representer. Find out more.

Create 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.

Next goal: Implement 130 practice exercises. Find out more.

Usage statistics

71 active practice exercises

Started

Attempts

Completions

Mentoring requests

Hello World

44,851

163,423 (avg. 3.6)

17,993 (40.1%)

20 (0.0%)

Armstrong Numbers

12,235

62,710 (avg. 5.1)

5,275 (43.1%)

1,344 (11.0%)

Isogram

5,432

40,125 (avg. 7.4)

3,176 (58.5%)

1,262 (23.2%)

Hamming

2,666

11,282 (avg. 4.2)

2,187 (82.0%)

497 (18.6%)

Grains

2,323

14,082 (avg. 6.1)

1,845 (79.4%)

387 (16.7%)

Difference of Squares

1,961

7,915 (avg. 4.0)

1,643 (83.8%)

277 (14.1%)

Square Root

1,638

5,813 (avg. 3.5)

1,091 (66.6%)

182 (11.1%)

Grade School

1,241

11,327 (avg. 9.1)

531 (42.8%)

120 (9.7%)

Binary Search

1,545

11,730 (avg. 7.6)

995 (64.4%)

168 (10.9%)

Rational Numbers

688

5,272 (avg. 7.7)

411 (59.7%)

70 (10.2%)

Circular Buffer

827

6,438 (avg. 7.8)

386 (46.7%)

60 (7.3%)

List Ops

732

4,804 (avg. 6.6)

375 (51.2%)

51 (7.0%)

Resistor Color

5,376

32,197 (avg. 6.0)

2,616 (48.7%)

623 (11.6%)

Pythagorean Triplet

579

2,550 (avg. 4.4)

266 (45.9%)

34 (5.9%)

Saddle Points

428

2,092 (avg. 4.9)

231 (54.0%)

26 (6.1%)

Allergies

520

1,649 (avg. 3.2)

337 (64.8%)

37 (7.1%)

Phone Number

484

3,055 (avg. 6.3)

298 (61.6%)

34 (7.0%)

Clock

572

2,553 (avg. 4.5)

338 (59.1%)

33 (5.8%)

Sieve

539

2,405 (avg. 4.5)

365 (67.7%)

29 (5.4%)

Robot Simulator

559

1,651 (avg. 3.0)

360 (64.4%)

30 (5.4%)

Pascal's Triangle

481

1,779 (avg. 3.7)

288 (59.9%)

26 (5.4%)

Binary

632

3,990 (avg. 6.3)

473 (74.8%)

31 (4.9%)

Queen Attack

385

1,210 (avg. 3.1)

288 (74.8%)

25 (6.5%)

Linked List

641

3,838 (avg. 6.0)

323 (50.4%)

64 (10.0%)

Darts

1,778

3,187 (avg. 1.8)

1,211 (68.1%)

69 (3.9%)

Resistor Color Duo

1,016

1,630 (avg. 1.6)

750 (73.8%)

16 (1.6%)

Resistor Color Trio

859

2,129 (avg. 2.5)

621 (72.3%)

18 (2.1%)

Acronym

1,767

6,073 (avg. 3.4)

1,145 (64.8%)

102 (5.8%)

Gigasecond

1,187

1,609 (avg. 1.4)

860 (72.5%)

129 (10.9%)

Space Age

864

1,812 (avg. 2.1)

646 (74.8%)

22 (2.5%)

Pangram

1,072

3,060 (avg. 2.9)

779 (72.7%)

39 (3.6%)

Word Count

1,372

2,535 (avg. 1.8)

618 (45.0%)

184 (13.4%)

Rail Fence Cipher

245

1,127 (avg. 4.6)

151 (61.6%)

7 (2.9%)

Matching Brackets

536

1,452 (avg. 2.7)

351 (65.5%)

51 (9.5%)

Nucleotide Count

628

2,966 (avg. 4.7)

432 (68.8%)

15 (2.4%)

RNA Transcription

702

2,019 (avg. 2.9)

514 (73.2%)

32 (4.6%)

Secret Handshake

343

1,670 (avg. 4.9)

224 (65.3%)

10 (2.9%)

Meetup

539

767 (avg. 1.4)

264 (49.0%)

8 (1.5%)

Pig Latin

221

1,347 (avg. 6.1)

131 (59.3%)

8 (3.6%)

Leap

925

2,065 (avg. 2.2)

742 (80.2%)

16 (1.7%)

Two Fer

374

1,110 (avg. 3.0)

286 (76.5%)

12 (3.2%)

Beer Song

603

1,951 (avg. 3.2)

391 (64.8%)

112 (18.6%)

Raindrops

598

1,310 (avg. 2.2)

460 (76.9%)

19 (3.2%)

Roman Numerals

622

7,256 (avg. 11.7)

392 (63.0%)

64 (10.3%)

Wordy

224

956 (avg. 4.3)

132 (58.9%)

11 (4.9%)

Bob

496

1,393 (avg. 2.8)

338 (68.1%)

13 (2.6%)

Complex Numbers

301

742 (avg. 2.5)

219 (72.8%)

3 (1.0%)

Sum of Multiples

477

991 (avg. 2.1)

303 (63.5%)

9 (1.9%)

Two Bucket

128

399 (avg. 3.1)

68 (53.1%)

0 (0.0%)

Anagram

472

1,081 (avg. 2.3)

302 (64.0%)

14 (3.0%)

Binary Search Tree

349

1,056 (avg. 3.0)

171 (49.0%)

27 (7.7%)

Say

174

657 (avg. 3.8)

91 (52.3%)

1 (0.6%)

ETL

236

754 (avg. 3.2)

146 (61.9%)

5 (2.1%)

Series

337

834 (avg. 2.5)

201 (59.6%)

3 (0.9%)

Diamond

225

761 (avg. 3.4)

140 (62.2%)

4 (1.8%)

Minesweeper

231

836 (avg. 3.6)

128 (55.4%)

5 (2.2%)

Run-Length Encoding

209

915 (avg. 4.4)

116 (55.5%)

5 (2.4%)

Atbash Cipher

310

1,039 (avg. 3.4)

197 (63.5%)

26 (8.4%)

Crypto Square

179

657 (avg. 3.7)

105 (58.7%)

0 (0.0%)

React

481

1,967 (avg. 4.1)

105 (21.8%)

14 (2.9%)

Prime Factors

254

637 (avg. 2.5)

153 (60.2%)

3 (1.2%)

Nth Prime

328

798 (avg. 2.4)

202 (61.6%)

5 (1.5%)

Perfect Numbers

269

812 (avg. 3.0)

187 (69.5%)

2 (0.7%)

Triangle

382

1,435 (avg. 3.8)

234 (61.3%)

6 (1.6%)

Collatz Conjecture

332

988 (avg. 3.0)

249 (75.0%)

24 (7.2%)

Luhn

271

1,676 (avg. 6.2)

171 (63.1%)

13 (4.8%)

Palindrome Products

233

807 (avg. 3.5)

114 (48.9%)

11 (4.7%)

All Your Base

288

838 (avg. 2.9)

152 (52.8%)

5 (1.7%)

Scrabble Score

243

768 (avg. 3.2)

169 (69.5%)

15 (6.2%)

Sublist

226

793 (avg. 3.5)

122 (54.0%)

7 (3.1%)

Largest Series Product

243

782 (avg. 3.2)

159 (65.4%)

2 (0.8%)

59 unimplemented practice exercises

Affine Cipher

Alphametics

Bank Account

Book Store

Bottle Song

Bowling

Change

Connect

Custom Set

D&D Character

DOT DSL

Dominoes

Error Handling

Flatten Array

Food Chain

Forth

Go Counting

Grep

Hangman

High Scores

House

ISBN Verifier

Killer Sudoku Helper

Kindergarten Garden

Knapsack

Ledger

Lens Person

Markdown

Matrix

Micro Blog

OCR Numbers

POV

PaaS I/O

Parallel Letter Frequency

Poker

Protein Translation

Proverb

REST API

Rectangles

Reverse String

Robot Name

Rotational Cipher

SGF Parsing

Satellite

Scale Generator

Simple Cipher

Simple Linked List

Spiral Matrix

State of Tic-Tac-Toe

Strain

Tournament

Transpose

Tree Building

Twelve Days

Variable Length Quantity

Word Search

Yacht

Zebra Puzzle

Zipper

Volunteers

262

siebenschlaefer

6,024

wolf99

3,778

ryanplusplus

3,639

+ 250 more

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66,971 students have developed their C skills on Exercism.

The C track needs attention ⚠️

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Create Practice Exercises

Usage statistics

We 💙 our volunteers

66,971
students have developed their C skills on Exercism.