🧠 algorithms core

A comprehensive, fast, and extensible algorithms library for Dart. Includes classic and modern techniques for lists, sets, maps, strings, and graphs — built with clean APIs and strong generics.

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• Actively maintained with ambitious roadmap (1,000+ algorithms planned)
• Type-safe generics across the library
• Readable code with clear documentation and tests

Environment: Dart SDK ≥ 3.7.2 (see pubspec.yaml).

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📦 Install algorithms core

Use in your Dart or Flutter project.

Dart

dart pub add algorithms_core

Flutter

flutter pub add algorithms_core

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🚀 Quick start algorithm

import 'package:algorithms_core/algorithms_core.dart';
import 'package:algorithms_core/graph_algorithms/weighted_edge.dart';

void main() {
  // List: binary search and sorting
  final idx = binarySearch<int>([1, 3, 5, 7, 9], 7);
  final sorted = mergeSort<int>([5, 2, 4, 6, 1, 3]);

  // String: algorithms
  final isPal = isPalindrome('A man a plan a canal Panama');
  final lcp = longestCommonPrefix(['flower', 'flow', 'flight']);

  // Graph: Dijkstra over weighted edges
  final graph = <String, List<WeightedEdge<String>>>{
    'A': [WeightedEdge('A', 'B', 1), WeightedEdge('A', 'C', 4)],
    'B': [WeightedEdge('B', 'C', 2)],
    'C': [],
  };
  final dist = dijkstra(graph, 'A');

  // Tree: binary tree operations
  final root = BinaryTreeNode<int>(10);
  root.left = BinaryTreeNode<int>(5);
  root.right = BinaryTreeNode<int>(15);
  final inorder = inorderTraversal(root);
  final isValid = validateBST(root);

  // Linked List: basic operations
  final list = LinkedListNode.fromList<int>([1, 2, 3, 4, 5]);
  final reversed = reverseLinkedList(list);
  final hasCycle = detectCycle(list);

  print([idx, sorted, isPal, lcp, dist, inorder, isValid, reversed, hasCycle]);
}

For a full tour, see example/algorithms_core_example.dart, example/tree_algorithms_example.dart, and example/linked_list_algorithms_example.dart.

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🧩 Algorithms included

List algorithms

• binary_search, linear_search
• merge_sort, quick_sort, bubble_sort, insertion_sort, selection_sort
• counting_sort (non-negative ints)
• reverse_list, find_max_min, find_duplicates, remove_duplicates
• kadanes_algorithm
• max_sum_subarray_of_size_k, min_sum, average_subarray, prefix_sum, two_sum_sorted
• rotate_array_right

Set algorithms

• has_duplicates, has_two_sum, has_unique_window
• disjoint_set (Union-Find), find_intersection, set_difference, is_frequency_unique

Map algorithms

• frequency_count, most_frequent_element, top_k_frequent
• group_by_key, first_non_repeated_element
• anagram_checker (generic list-based)
• two_sum (indices), lru_cache, length_of_longest_substring

String algorithms

• reverse_string, palindrome_checker, anagram_checker
• brute_force_search, kmp_search, rabin_karp_search
• longest_common_prefix, longest_palindromic_substring
• edit_distance, string_compression, count_vowels_consonants

Graph algorithms (new)

• bfs, dfs, topological_sort
• connected_components, cycle_detection (directed/undirected), bipartite_graph
• shortest_path (unweighted BFS), weighted_edge (utility)
• dijkstra, bellman_ford, floyd_warshall
• mst_kruskal, mst_prim
• kosaraju_scc, articulation_points, union_find (typedef)

Tree algorithms (new)

• binary_tree_node (generic tree node)
• tree_traversals (inorder, preorder, postorder)
• level_order_traversal (BFS)
• tree_depth (height calculation)
• invert_tree (mirror tree)
• lowest_common_ancestor (LCA)
• validate_bst (BST validation)
• tree_diameter (longest path)
• balanced_tree_check (height-balanced check)
• tree_serialization (serialize/deserialize)
• zigzag_traversal (alternating level order)

Linked List algorithms (new)

• linked_list_node (generic singly linked list node)
• doubly_linked_list_node (generic doubly linked list node)
• insert_delete_at_position (insert/delete at specific positions)
• reverse_linked_list (iterative, recursive, group reverse, reverse between)
• detect_cycle (Floyd's cycle detection algorithm)
• merge_sorted_lists (merge two sorted linked lists)
• remove_nth_from_end (remove nth node from end)
• palindrome_linked_list (check if linked list is palindrome)
• intersection_of_lists (find intersection point of two lists)

Each function includes Dartdoc with usage and time/space complexity.

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📚 Usage notes

• Import everything via package:algorithms_core/algorithms_core.dart.
• Sorting/searching functions use T extends Comparable where appropriate.
• Weighted graph utilities use WeightedEdge<T>.
• Algorithms are pure and side-effect free unless documented otherwise.

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🧪 Running tests

dart test

All tests pass in the repository (see test/).

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Key Algorithms

Algorithm	Description
binary_search	Fast and efficient binary search on a sorted list.
merge_sort	Stable sorting algorithm with excellent performance.
quick_sort	Fast sorting algorithm with good average-case performance.
kadanes_algorithm	Finds the maximum sum of a contiguous subarray.
dijkstra	Finds the shortest path in a weighted directed graph.
bellman_ford	Shortest path algorithm that handles negative weights and detects negative cycles.
floyd_warshall	Finds shortest paths between all pairs of nodes in a graph.
bfs (Breadth-First Search)	Graph traversal method for connectivity and shortest unweighted paths.
dfs (Depth-First Search)	Graph traversal method for cycle detection, classification, and orderings.
topological_sort	Orders nodes in a directed acyclic graph (DAG).
disjoint_set (Union-Find)	Data structure for managing disjoint sets and connectivity.
kmp_search (Knuth-Morris-Pratt)	Efficient substring search using prefix tables.
rabin_karp_search	Substring search algorithm based on hashing.
longest_common_prefix	Finds the longest common prefix among a list of strings.
lowest_common_ancestor (LCA)	Finds the lowest common ancestor node in a tree.
validate_bst	Validates whether a binary tree is a binary search tree.
reverse_linked_list	Reverses a singly or doubly linked list.
detect_cycle (Floyd’s Cycle Detection)	Detects cycles in a linked list.
mst_kruskal	Constructs a minimum spanning tree using Kruskal's algorithm.
mst_prim	Constructs a minimum spanning tree using Prim's algorithm.

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🤝 Contributing

Contributions are welcome!

• Add new algorithms or optimize existing ones
• Improve docs and examples
• Increase test coverage

Open a PR with a brief description and test cases.

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🗺️ Roadmap (short-term)

• Expand graph algorithms (SPFA, Johnson, Edmonds-Karp, Dinic)
• Add tree/heap/DP/geometry modules
• Benchmarks and performance docs

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📄 License

MIT. See LICENSE.