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Exercises

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1579 mentors

73,332
students have developed their C skills on Exercism.

Students

73,332

Submissions

545,532

Mentoring Discussions

6,740

The C track needs attention ⚠️

Building

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Use your knowledge to build the C track itself

77 contributors

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

502,635

Test Run Pass Rate

12.5% (62600)

Test Run Fail Rate

19.0% (95665)

Test Run Error Rate

68.5% (344370)

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

73 active practice exercises

Started

Attempts

Completions

Mentoring requests

Hello World

50,468

188,097 (avg. 3.7)

19,969 (39.6%)

20 (0.0%)

Armstrong Numbers

13,681

71,837 (avg. 5.3)

5,854 (42.8%)

1,419 (10.4%)

Isogram

6,145

49,069 (avg. 8.0)

3,521 (57.3%)

1,296 (21.1%)

Hamming

3,099

13,732 (avg. 4.4)

2,535 (81.8%)

515 (16.6%)

Grains

2,710

17,244 (avg. 6.4)

2,148 (79.3%)

400 (14.8%)

Difference of Squares

2,276

9,456 (avg. 4.2)

1,923 (84.5%)

286 (12.6%)

Square Root

1,913

6,992 (avg. 3.7)

1,293 (67.6%)

190 (9.9%)

Grade School

1,487

13,874 (avg. 9.3)

628 (42.2%)

129 (8.7%)

Binary Search

1,761

13,547 (avg. 7.7)

1,154 (65.5%)

172 (9.8%)

Rational Numbers

799

6,192 (avg. 7.7)

482 (60.3%)

71 (8.9%)

Circular Buffer

957

7,201 (avg. 7.5)

455 (47.5%)

65 (6.8%)

List Ops

848

5,558 (avg. 6.6)

455 (53.7%)

55 (6.5%)

Reverse String

392 (avg. 5.8)

44 (64.7%)

2 (2.9%)

Resistor Color

5,481

32,799 (avg. 6.0)

2,688 (49.0%)

624 (11.4%)

Pythagorean Triplet

670

2,973 (avg. 4.4)

323 (48.2%)

35 (5.2%)

Saddle Points

501

2,403 (avg. 4.8)

281 (56.1%)

28 (5.6%)

Allergies

594

1,931 (avg. 3.3)

390 (65.7%)

37 (6.2%)

Phone Number

562

3,617 (avg. 6.4)

358 (63.7%)

38 (6.8%)

Clock

663

2,876 (avg. 4.3)

407 (61.4%)

35 (5.3%)

Sieve

618

2,660 (avg. 4.3)

435 (70.4%)

32 (5.2%)

Robot Simulator

645

1,901 (avg. 2.9)

424 (65.7%)

35 (5.4%)

Pascal's Triangle

547

1,955 (avg. 3.6)

335 (61.2%)

29 (5.3%)

Binary

719

4,350 (avg. 6.1)

546 (75.9%)

34 (4.7%)

Queen Attack

443

1,456 (avg. 3.3)

336 (75.8%)

27 (6.1%)

Linked List

732

4,517 (avg. 6.2)

384 (52.5%)

69 (9.4%)

Darts

1,842

3,470 (avg. 1.9)

1,260 (68.4%)

69 (3.7%)

Resistor Color Duo

1,069

1,756 (avg. 1.6)

793 (74.2%)

16 (1.5%)

Resistor Color Trio

900

2,217 (avg. 2.5)

659 (73.2%)

19 (2.1%)

Acronym

1,827

6,550 (avg. 3.6)

1,195 (65.4%)

108 (5.9%)

Gigasecond

1,232

1,677 (avg. 1.4)

902 (73.2%)

131 (10.6%)

Space Age

919

1,971 (avg. 2.1)

692 (75.3%)

22 (2.4%)

High Scores

66 (avg. 2.4)

16 (57.1%)

2 (7.1%)

Pangram

1,135

3,464 (avg. 3.1)

832 (73.3%)

42 (3.7%)

Word Count

1,420

2,657 (avg. 1.9)

648 (45.6%)

188 (13.2%)

Rail Fence Cipher

279

1,194 (avg. 4.3)

178 (63.8%)

8 (2.9%)

Matching Brackets

576

1,544 (avg. 2.7)

381 (66.1%)

51 (8.9%)

Nucleotide Count

669

3,204 (avg. 4.8)

468 (70.0%)

17 (2.5%)

RNA Transcription

740

2,113 (avg. 2.9)

548 (74.1%)

33 (4.5%)

Secret Handshake

388

1,887 (avg. 4.9)

259 (66.8%)

13 (3.4%)

Meetup

569

828 (avg. 1.5)

288 (50.6%)

9 (1.6%)

Pig Latin

248

1,402 (avg. 5.7)

153 (61.7%)

8 (3.2%)

Leap

988

2,301 (avg. 2.3)

798 (80.8%)

19 (1.9%)

Two Fer

425

1,251 (avg. 2.9)

327 (76.9%)

13 (3.1%)

Beer Song

642

2,086 (avg. 3.2)

415 (64.6%)

112 (17.4%)

Raindrops

631

1,383 (avg. 2.2)

488 (77.3%)

19 (3.0%)

Roman Numerals

677

8,520 (avg. 12.6)

434 (64.1%)

65 (9.6%)

Wordy

245

1,004 (avg. 4.1)

152 (62.0%)

11 (4.5%)

Bob

525

1,527 (avg. 2.9)

361 (68.8%)

14 (2.7%)

Complex Numbers

332

826 (avg. 2.5)

249 (75.0%)

3 (0.9%)

Sum of Multiples

503

1,033 (avg. 2.1)

323 (64.2%)

9 (1.8%)

Two Bucket

149

426 (avg. 2.9)

84 (56.4%)

0 (0.0%)

Anagram

494

1,187 (avg. 2.4)

320 (64.8%)

14 (2.8%)

Binary Search Tree

377

1,148 (avg. 3.0)

194 (51.5%)

28 (7.4%)

Say

194

681 (avg. 3.5)

105 (54.1%)

1 (0.5%)

ETL

260

784 (avg. 3.0)

166 (63.8%)

5 (1.9%)

Series

365

873 (avg. 2.4)

221 (60.5%)

4 (1.1%)

Diamond

251

880 (avg. 3.5)

163 (64.9%)

4 (1.6%)

Minesweeper

255

865 (avg. 3.4)

144 (56.5%)

5 (2.0%)

Run-Length Encoding

233

1,026 (avg. 4.4)

134 (57.5%)

7 (3.0%)

Atbash Cipher

331

1,076 (avg. 3.3)

215 (65.0%)

27 (8.2%)

Crypto Square

203

733 (avg. 3.6)

122 (60.1%)

0 (0.0%)

React

526

2,097 (avg. 4.0)

122 (23.2%)

15 (2.9%)

Prime Factors

280

706 (avg. 2.5)

176 (62.9%)

3 (1.1%)

Nth Prime

351

882 (avg. 2.5)

223 (63.5%)

5 (1.4%)

Perfect Numbers

292

877 (avg. 3.0)

210 (71.9%)

2 (0.7%)

Triangle

414

1,552 (avg. 3.7)

259 (62.6%)

6 (1.4%)

Collatz Conjecture

369

1,136 (avg. 3.1)

281 (76.2%)

25 (6.8%)

Luhn

298

1,822 (avg. 6.1)

194 (65.1%)

13 (4.4%)

Palindrome Products

255

846 (avg. 3.3)

129 (50.6%)

11 (4.3%)

All Your Base

310

873 (avg. 2.8)

167 (53.9%)

5 (1.6%)

Scrabble Score

268

814 (avg. 3.0)

189 (70.5%)

16 (6.0%)

Sublist

249

830 (avg. 3.3)

140 (56.2%)

8 (3.2%)

Largest Series Product

273

858 (avg. 3.1)

177 (64.8%)

2 (0.7%)

57 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

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

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

273

siebenschlaefer

6,256

wolf99

3,810

ryanplusplus

3,810

+ 261 more

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Become an Exercism Volunteer

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Discord

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Getting started

Mentoring

Docs

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About Exercism

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73,332 students have developed their C skills on Exercism.

The C track needs attention ⚠️

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Usage statistics

Build Analyzers

Build Representers

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Usage statistics

We 💙 our volunteers

73,332
students have developed their C skills on Exercism.