A typescript implementation of Circular Stack.

Install

• npm

  npm install --save @algorithm.ts/stack

• pnpm

  pnpm 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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