Competitive Programming

  • Practice and coursework
  • Practice Archive
  • 2023
  • Open source

Java, Python, C++, SQL

Source code

These repositories hold the problems I solved while practising competitive programming during my B.Tech at The NorthCap University. They cover LeetCode, CodeChef, Codeforces, the CSES Problem Set and Coding Ninjas Studio. A few files come from GeeksforGeeks, TCS CodeVita, HackerEarth and Advent of Code. Most of the code is Java, and 293 of the 381 commits are from 2023.

It is practice from my university years, not product work. No file in these repositories records a rating, a rank or a contest result, so this page claims none. What the files do show is how much I practised, where, in which language, and which habits I would fix.

gitsession

# solution files, Markdown left outcd leetcode-contests-and-problem-solutionsgit ls-files Problems | grep -vc '\.md$'914git ls-files Contests | grep -vc '\.md$'84cd ../cses-problem-set-solutionsgit ls-files | grep -c '\.cpp$'288

5 commands3 lines of output

Contest and practice solutions from LeetCode, CodeChef, Codeforces, CSES and Coding Ninjas Studio, mostly in Java, committed between 2023 and 2025.
Chapter
Practice and coursework
Category
Practice Archive
Year
Availability
Open source
Last commit
stack4 parts
  • Java
  • Python
  • C++
  • SQL

Competitive Programming, Algorithms, Data Structures, Java, LeetCode

One contest, one commit

Contests were the backbone. LeetCode weekly and biweekly rounds, CodeChef Starters, Codeforces Div. 3 rounds and Coding Ninjas weekend contests each left a folder behind. Commit messages such as Added CodeChef STARTERS 109 Solutions show the rhythm: one contest, one commit. Some contest folders also carry a README table linking each problem to its file. Between contests I solved standalone LeetCode problems and part of the Top Interview 150 study plan. I wrote nearly all of it in Java, the language of my second programming course. Python appears for some LeetCode problems, SQL for its database problems, and C++ in the CSES set and the Coding World Cup files.

One repository per platform

Until December 2023 everything lived in one repository, Competetive-Programming-Contests-Solutions. On 6 December I split it, and CodeChef, Codeforces and Coding Ninjas Studio each got their own repository that day. Every solution is one file named after its problem, such as Problems/1. Two Sum.java. LeetCode files hold the Solution class the judge calls, while 192 of the 198 CodeChef Java files are whole programs with a main method. Contest folders follow each site, from Contests/Weekly Contests/STARTERS 115/ to Contests/Codeforces Round/Codeforces Round 913 (Div. 3)/. CSES uses one folder per category. The split had a cost. Each new repository began with one bulk Added Solutions commit, so the history of earlier contests stayed in the old log.

Counting the files

I counted with git ls-files, leaving out Markdown, licences, compiled .class files and two editor scratch files named tempCodeRunnerFile.java.

PlatformRepositoriesFiles
LeetCodeleetcode-contests-and-problem-solutions1,034
CodeChefcodechef-contests-and-problem-solutions, ncu-hacks-1.0206
Codeforcescodeforces-contests-and-problem-solutions25
CSEScses-problem-set-solutions303
Coding Ninjas Studiocoding-ninjas-studio-contests-challenges-and-problem-solutions378
Other platformsdsa-practice, competitive-programming-practice, java-practice49

LeetCode’s 1,034 files are 914 standalone problems covering 834 problem numbers, 84 solutions from 25 contests, and 36 from Top Interview 150. CodeChef spans 33 contests, 29 of them Starters. ncu-hacks-1.0 repeats ten of those files from NCU Hacks 1.0, a two-round contest hosted on CodeChef. Codeforces spans ten rounds. Coding Ninjas includes 180 files from the 2023 Coding World Cup, often one problem in two languages. Across all six rows, 1,371 of the 1,995 files are Java.

What I would change

Nothing records a verdict. No file says whether it was accepted, and there are no tests. Each file is a submission I kept, not one I can prove passed. Contest numbering also changes between rounds, so contest work cannot be joined to Problems/ by number. If I started again, every file would open with a one-line header giving the verdict and the key idea.

What this is not

google-competitive-programming-contests holds no solutions of mine. It is a copy of Google’s published problem archive. It covers Code Jam, Kick Start, Code Jam to I/O for Women, Distributed Code Jam, Hash Code and the Farewell Rounds. That is 732 problem packages with statements, analyses, test data and judges. The 288 C++ files in the CSES repository need a caveat too. They arrived in one commit with no history of being worked through, so I treat them as a reference set. Ten of the 15 Python and Java files beside them came in two later commits. The last new solution was committed in March 2025, and none of these repositories is active now.

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