barehands

backtracking 6

Fallback Chain Selector medium

backtracking, subset selection, pruning

backtrackingnetworkingscheduling

c

Feature Flag Compatibility Solver medium

constraint satisfaction, backtracking, recursion

backtrackingconfiguration

c

Glob / Path Pattern Matcher medium

strings, recursion, backtracking, wildcards

backtrackingstrings

c

Migration Step Ordering with Optional Steps medium

topological sort, backtracking, constraint satisfaction

backtrackinggraphsconfiguration

c

Permission / Role Assignment Solver medium

backtracking, constraint satisfaction, RBAC

backtrackinggraphsconfiguration

c

CIDR Subnet Allocator medium

backtracking, assignment, recursion

backtrackingnetworkingconfiguration

c

caching 3

Consistent Hashing medium

consistent hashing, virtual nodes, hash ring

cachingdistributed

c

LFU Cache hard

cache eviction, frequency counting, LRU tie-break

cachingdata-structures

c

SIEVE Cache medium

cache eviction, doubly-linked list, second-chance

cachingdata-structures

c

data-structures 14

Binary Heap / Priority Queue medium

data structures, heaps, implicit trees

data-structuresc

c

Bitset medium

bit manipulation, popcount, fixed-size set

data-structuresc

c

Bloom Filter medium

probabilistic data structures, bit manipulation, hashing

data-structuresc

c

B-Tree (ordered map) hard

data structures, balanced trees, ordered map

data-structurestrees

c

Fenwick Tree (Binary Indexed Tree) medium

data structures, prefix sums, bit manipulation

data-structuresc

c

Hash Table (Open Addressing) medium

hash table, open addressing, linear probing, tombstones

data-structuresc

c

Interval / Range Index medium

sorted arrays, binary search, half-open ranges

data-structuressearch

c

Intrusive Linked List medium

intrusive data structures, doubly-linked list, container_of

data-structuresc

c

LRU Cache medium

data structures, caching

data-structurescaching

c

LSM Memtable + Merge medium

storage engines, ordered data, k-way merge, tombstones

data-structuresstorage

c

Ring Buffer medium

ring buffer, FIFO queue, fixed-capacity, no allocation

data-structuresc

c

Skip List medium

data structures, ordered map, probabilistic balancing

data-structurestrees

c

Trie (Prefix Tree) medium

data structures, strings, prefix trees

data-structuresc

c

Union-Find (Disjoint Set) medium

data structures, union-find, amortized analysis

data-structuresc

c

encoding 8

Base32 (RFC 4648) medium

bit manipulation, encoding

encodingc

c

Base64 (RFC 4648) medium

bit manipulation, encoding, RFC 4648

encodingc

c

Bit Reader / Writer medium

bit manipulation, serialization, codecs

encodingc

c

CRC-32 Checksum medium

bit manipulation, checksums, polynomials

encodingc

c

Hex Codec easy

bit manipulation, encoding

encodingc

c

Run-Length Encoding easy

compression, encoding

encodingc

c

UTF-8 Decode & Validate medium

bit manipulation, encoding, Unicode

encodingc

c

Varint (LEB128) medium

variable-length integers, bit manipulation, encoding

encodingc

c

graphs 6

Outage Blast Radius medium

graphs, BFS, reversed edges, shortest paths

graphsresilience

c

CNAME / Redirect Chain Resolver easy

chain following, cycle detection, hop budget

graphsnetworking

c

Config Include Resolver medium

graphs, DFS, recursion, cycle detection

graphsconfiguration

c

Service Dependency Resolver medium

graphs, topological sort, cycle detection

graphsorchestration

c

RBAC Role Inheritance medium

graphs, DFS, transitive closure, cycle detection

graphsauthorization

c

Trace Tree & Critical Path medium

graphs, trees, DFS, longest path

graphsobservability

c

leetcode 5

Binary Search easy

binary search, sorted array

leetcodesearchalgorithms

c

Valid Anagram easy

counting, strings

leetcodestringshash-map

c

Maximum Subarray medium

Kadane's algorithm, dynamic programming

leetcodedynamic-programmingarray

c

Two Sum easy

arrays, search

leetcodearrayhash-map

c

Valid Parentheses easy

stack, string scan

leetcodestackstrings

c

memory 3

Arena Allocator medium

bump allocator, alignment, memory management

memoryc

c

Free-List Allocator hard

allocator, malloc/free, block splitting, coalescing

memoryc

c

Slab / Pool Allocator medium

allocators, free lists, fixed-size objects

memoryc

c

networking 2

Message Framing (length-prefix) medium

stream framing, length-prefix protocol, partial reads

networkingprotocols

c

RESP mini-server (Redis) medium

wire-protocol parsing, RESP, in-memory store

networkingprotocols

c

numeric 1

Bignum (Arbitrary-Precision Arithmetic) medium

numeric algorithms, strings, carries

numericc

c

parsing 2

JSON Tokenizer (jsmn-style) hard

parsing, state machines, zero-copy

parsingc

c

RPN Expression Evaluator medium

stacks, parsing, expression evaluation

parsingc

c

scheduling 1

Job Placement Scheduler medium

backtracking, constraint satisfaction, scheduling

schedulingbacktracking

c

strings 2

Edit Distance (Levenshtein) medium

dynamic programming, strings

stringsc

c

Substring Search (KMP) medium

strings, algorithms, the failure function

stringsc

c

Challenges

backtracking 6

caching 3

data-structures 14

encoding 8

graphs 6

leetcode 5

memory 3

networking 2

numeric 1

parsing 2

scheduling 1

strings 2