project-algorithms

A personal training ground for data structures & algorithms — solutions and from-scratch implementations written while studying, organized by topic. Mostly JavaScript and Python, no build step: every file runs on its own.

Layout

Folder	Files	What's inside
dynamic-programming/	16 · JS	The same classic DP problems solved twice — top-down memoization-* and bottom-up tabulation-* (fib, canSum, howSum, bestSum, canConstruct, countConstruct, allConstruct, gridTraveler). Seeing both side by side is the point.
leet-code/	25 · JS + Py	LeetCode solutions named NNNN_topic_slug by problem number (e.g. 0020_stack_valid_parentheses.js, 0133_graph_clone_graph.py). Grouped loosely by theme in the slug: stack, graph, arrays.
graphs/disjoin_set/	5 · Py	Union-Find built up in stages: quick_find → quick_union → union_by_rank → path_compression → path_compression_optimized.
stack/	6 · JS	Stack implementations (array, object, linked-list) and applications (decimal→binary, base converter).
queue/	4 · JS	Queue + deque, hot-potato, palindrome checker.
sort/	3 · Py	Quick sort (in-place & simple), selection sort.
search/	2 · Py	Binary search and linear ("minor") search.
hackerank/	3 · JS	HackerRank warm-ups (bon-appetit, drawing-book, sales-match).
root	2 · JS	Standalone exercises: frontlead-flatten.js, histogram.js.

Naming conventions

• memoization-* / tabulation-* — the two DP approaches to the same problem.
• NNNN_topic_slug.ext — LeetCode files, prefixed with the zero-padded problem number so they sort in numeric order.

Running an example

No dependencies to install — just run a file directly:

# JavaScript (Node)
node dynamic-programming/memoization-fibonnaci.js
node leet-code/0020_stack_valid_parenteheses.js

# Python 3
python3 sort/quick_sort.py
python3 graphs/disjoin_set/union_by_rank.py

Languages

JavaScript (Node.js) · Python 3