stack

@algorithm.ts/stack

A typescript implementation of Circular Stack.

Install

• npm

  npm install --save @algorithm.ts/stack

• yarn

  yarn add @algorithm.ts/stack

Usage

CircularStack

Circular stack is a stack structure, the main purpose of its design is to reuse space as much as possible on the basis of ordinary stacks. Circular stacks usually need to specify a capacity, if the number of elements in the stack exceeds the capacity, only the most recent capacity elements are kept in the stack. Other operations are the same as ordinary stacks.

• ICircularStack: CircularStack implements the ICircularStack interface.

  Signature	Description
  readonly capacity: number	The capacity of stack, which also means the max elements of the stack.
  readonly size: number	The count of the elements in the stack.
  at(index: number): T | undefined	Get the element at the given index.
  clear(): void	Clear the stack.
  consuming(): IterableIterator<T>	Popup the elements from the stack one by one.
  count(filter: (element: T, index: number) => boolean): number	Count the elements in the stack which matched by the filter.
  pop(newElement?: T): T | undefined	Popup the top element, and push the given newElement if it is not undefined.
  push(element: T): this	Push a element into the stack.
  rearrange(filter: (element: T, index: number) => boolean): void	Only preserve the elements matched the filter.
  resize(capacity: number): void	Resize the capacity of stack with the given size.
  top(): T|undefined	Get the top element from the stack.
  update(index: number, element: T): void	Change the element at the given index.

• ICircularStackProps

  export interface ICircularStackProps {
    /**
    * Initial capacity of the circular stack.
    */
    capacity?: number
  }

Example

• Basic -- CircularStack

  import { CircularStack } from '@algorithm.ts/stack'
  
  const stack = new CircularStack<{ name: string }>({ capacity: 100 })
  
  // Append a element to the end of the stack.
  stack.push({ name: 'alice' }) // => 0
  stack.push({ name: 'bob' }) // => 1
  stack.size          // => 2
  
  // Get the front element of the stack.
  stack.top()         // => { name: 'bob' }
  
  // Take off the first element of the stack.
  stack.pop()         // => { name: 'bob' }
  stack.size          // => 1

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