二叉樹

Self-Balancing Binary Search Tree for Dart. BST is implemented as Iterable. There are many operations such as greaterThan, lessThanOrEqual (create sublist), max , min etc.

Features

void main() {
  final myNumbers = BinaryTree([10, 8, 16, 4, 9, 13, 25, 2, 6, 12, 26, 14, 18]);
}

Binary tree stores values as a binary search tree.
For more information : Binary Search Tree.

A Self-Balancing AVL type tree is used, which balances the depth of the nodes.
For more information : Self Balancing Binary Search Tree , AVL Tree.

Usage

Use Case

You can see if you need it by looking at the benchmarks given below. It is generally advantageous in keeping long and sorted datasets. Its advantage is not noticeable on short datasets.

Benchmark scenarios

Type

Binary Tree objects must be Comparable

All of num , String , Duration etc. are Comparable.

You can define your objects as Comparable.

Comparable Documentation

void main() {
  final myLetters = BinaryTree<String>(["a", "c", "b"]);
  final myDates = BinaryTree<DateTime>([DateTime.now()]);
}

Basic operations

void main() {
  final myNumbers = BinaryTree([ 
    /*initial*/
  ]);
  myNumbers.insert(value);
  myNumbers.remove(value);
  myNumbers.contains(value);
  
}

Iterator

You can create an Iterator by "startsWith" or "endsWith" given element.

f() {
  final myNumbers = BinaryTree([10, 8, 16, 4, 9, 13, 25, 2, 6, 12, 26, 14, 18]);
  final iterator = myNumbers.iteratorFrom(8, greaterThan: true, equal: false); // defaults
  while (iterator.moveNext()) {
    print(iterator.current); // 9 , 10 ... 26
  }
}

You can also define bounds

f() {
  final myNumbers = BinaryTree([10, 8, 16, 4, 9, 13, 25, 2, 6, 12, 26, 14, 18]);
  final iterator = myNumbers.iteratorFrom(8, bound: Bound(13, equal: true));
  while (iterator.moveNext()) {
    print(iterator.current); // 9 , 10 ... 13
  }
}

toList

You can create new lists using range iterators.

f() {
  final myNumbers = BinaryTree([10, 8, 16, 4, 9, 13, 25, 2, 6, 12, 26, 14, 18]);

  myNumbers.lessThan(16);

  /// 14 , 13 , ... 2
  myNumbers.lessThanOrEqual(16);

  /// 16 , 14 , 13 , ... 2
  myNumbers.greaterThan(16);

  ///  25 , 26
  myNumbers.greaterThanOrEqual(16);

  /// 16 , 25 , 26

  /// custom bound
  myNumbers.listFrom(16, bound: Bound(13, equal: true));

  /// 16 , 14 , 13

}