Coding Problems

A long-term coding practice repository for keeping each problem in a self-contained folder with a short guide, starter code, and starter tests.

Current repository snapshot

• Total problem folders currently stored: 370 (all currently under leetcode/)
• Platforms present in the repository tree: 9
• Build / IDE output folders (for example out/) are ignored and should not be committed

Platform status

• GitHub only stores files, not empty folders. This repo includes minimal .gitkeep placeholder files so the full platform folder structure is visible on GitHub.

Stored vs solved

• Stored = number of problem folders currently present for that platform
• Solved = number of problems you have marked as solved (✅) in that platform index README

Platform	Stored problem folders	Solved	Solved Tracker	Stored problem folders live under
atcoder	0	0	⬜	atcoder/
codechef	0	0	⬜	codechef/
codeforces	0	0	⬜	codeforces/
cses	0	0	⬜	cses/
geeksforgeeks	0	0	⬜	geeksforgeeks/
hackerrank	0	0	⬜	hackerrank/
interviewbit	0	0	⬜	interviewbit/
leetcode	370	37	✅	leetcode/
spoj	0	0	⬜	spoj/

Active structure in this repository

Every platform currently uses the same top-level difficulty buckets that already exist in the tree:

platform/
├─ easy/
├─ medium/
├─ hard/
└─ advanced/

Inside each difficulty folder, reusable topic folders are used to keep problems discoverable and consistent.

Current topic folders available under LeetCode difficulty buckets

• arrays
• backtracking
• bfs
• binary_search
• binary_search_tree
• binary_tree
• bit_manipulation
• deque
• design
• dfs
• dynamic_programming
• fenwick_tree
• geometry
• graph
• greedy
• hash_map
• hash_set
• heap
• implementation
• intervals
• linked_hash_map
• linked_list
• math
• matrix
• monotonic_queue
• monotonic_stack
• number_theory
• prefix_sum
• priority_queue
• queue
• recursion
• segment_tree
• shortest_path
• simulation
• sliding_window
• sorting
• stack
• strings
• topological_sort
• trees
• trie
• two_pointers
• uncategorized
• union_find

Problem folder pattern

Each stored problem folder follows this naming convention:

problem_number_problem_slug/

Examples:

• 1_two_sum
• 26_remove_duplicates_from_sorted_array
• 100_same_tree

What each Java problem folder contains

Each Java-focused folder is designed to stand on its own and usually contains:

• README.md - a detailed, easy-to-read summary of the problem
• one Java starter class with the main method signature to implement
• one Java starter test file with suggested test cases or smoke-test notes

LeetCode index

Use leetcode/README.md for the detailed master index that lists:

• the exact folder path for every stored LeetCode problem
• its difficulty
• its primary topic category
• its problem number and title