| 551 | Componente tare conexe | Arhiva Educationala | Arhiva educationala | N/A |
| 552 | Compresie | Eugen Nodea | OJI 2012 - clasa a 10-a | N/A |
| 553 | Compress | Din Folclor | Infoarena Monthly 2012, Runda 5 | N/A |
| 554 | Compunere | Adrian Budau | Algoritmiada 2015, Runda 2 | N/A |
| 555 | Compus | Emanuela Cerchez | OJI 2003, clasele 11-12 | N/A |
| 556 | Comun | Lucian Bicsi | ONI 2019, clasa a 9-a, ziua 1 | N/A |
| 557 | Concert | Andrei Gonczi | info-arena 1.0 |      4/5 |
| 558 | Concert2 | Gemene Narcis - Gabriel, Inelus Gabriel | Infoarena Monthly 2014, Runda 3 |      2/5 |
| 559 | Concurs | Ionel Corneliu Gog | info-arena 1.0 |      3/5 |
| 560 | Concurs2 | Radu Visinescu | OJI 2008, clasa a 9-a | N/A |
| 561 | Conexidad | Mihai Calancea | OJI 2019, clasele 11-12 | N/A |
| 562 | Conexiuni | Adrian Airinei | Algoritmiada 2010, Runda Finala | N/A |
| 563 | Confuzie | Andrei Parvu | ONI 2013 Clasele 11-12 | N/A |
| 564 | Congr | Marius Stroe | Stelele Informaticii 2010 | N/A |
| 565 | Connect | Martin Kopchev | Shumen 2019 Juniori | N/A |
| 566 | Connect the Tree | Bogdan Ioan Popa | IIOT 2021-22 Runda 3 | N/A |
| 567 | Consecutive | Andreas Chelsau | ACM ICPC - Romanian Programming Contest 2016 | N/A |
| 568 | Conserve | Cristian Cadar | Lista lui Francu | N/A |
| 569 | Consiliul tribului | Mihai Patrascu | BOI 2003 |      4/5 |
| 570 | Consir | Adrian Airinei | Autumn Warmup 2007, Runda 3 | N/A |
| 571 | Constant | George Marcus | Concursul National de Informatica "Adolescent Grigore Moisil" |      5/5 |
| 572 | Contrasens | Eugenie Daniel Posdarascu | Algoritmiada 2016 - Runda 4 - Juniors | N/A |
| 573 | Control | Mihai Ciucu | All You Can Code 2008 |      5/5 |
| 574 | Controlor | Andrei Grigorean | Algoritmiada 2012, Runda 3 | N/A |
| 575 | Convertor | Ada Solcan, Alex Palcuie | ROSEdu CDL | N/A |
| 576 | Cool | Eugen Nodea | OJI 2014 - clasa a 9-a | N/A |
| 577 | Copaci | Stefan Gheorghe | info-arena 1.0 |      3/5 |
| 578 | Copaci 2 | Mircea Bogdan Pasoi | .campion 2007-2008, Runda 1 | N/A |
| 579 | Copaci3 | Din Folclor | Summer Challenge 2009, Runda 3 | N/A |
| 580 | Copaci4 | Vlad Ionescu | ONI 2012 - clasa a 9-a | N/A |
| 581 | Copacul Smenar | Florin Chirica | Concursul National de Informatica "Adolescent Grigore Moisil" 17 | N/A |
| 582 | Copii | Paul-Dan Baltescu | Algoritmiada 2010, Runda 4 | N/A |
| 583 | Copii2 | Marius Tiba | ONI 2011 - Baraj | N/A |
| 584 | Copii3 | Alexandru Petrescu, Andrei Popa, Mihai Calancea, Tamio-Vesa Nakajima | Algoritmiada 2018 Runda Maraton | N/A |
| 585 | Coprime | Andrei Grigorean | Algoritmiada 2009, Runda 1 | N/A |
| 586 | Copșa Mică | Adrian Budau, Vlad Gavrila | Lot Râmnicu Vâlcea 2015 - Baraj 3 Seniori | N/A |
| 587 | Core2 | Mugurel Ionut Andreica | Happy Coding 2008 | N/A |
| 588 | Cosmar | Bogdan Ciobanu | InfoPro, Runda 3, Grupa A | N/A |
| 589 | Costperm | Serban Andrei Stan | FMI No Stress 2012 | N/A |
| 590 | Costsq | Mugurel Ionut Andreica | Selectie echipe ACM ICPC, UPB 2009 | N/A |
| 591 | Costuri | Marius Nicoli | PreOJI 2017 | N/A |
| 592 | Count | Silviu-Ionut Ganceanu | preONI 2006 Runda 3 |      4/5 |
| 593 | Countbst | Marian Darius | Lot Seniori Tulcea 2018, baraj 2 | N/A |
| 594 | Countfefete | Teodor Ionescu | ONI 2018, Baraj | N/A |
| 595 | Countperm | Tamio-Vesa Nakajima | Algoritmiada 2022, Runda 3 | N/A |
| 596 | Cover | Adrian Vladu | Baraj ONI 2007 | N/A |
| 597 | Covor | Andrei Grigorean | Algoritmiada 2010, Runda Finala | N/A |
| 598 | Covrigi | Theodor Moroianu | FMI No Stress 9 | N/A |
| 599 | Cowfood | Adrian Vladu | preONI 2006 Runda 3 |      4/5 |
| 600 | Cp | Mugurel Ionut Andreica | Happy Coding 2008 | N/A |