class Stack
{
	constructor () {
		this.items = []
	}

	push (item) {
		this.items.push(item)
	}


	pop () {
		return this.items.pop()
	}

	peek () {
		return this.items[this.items.length - 1]
	}

	isEmpty () {
		return this.items.length === 0
	}

	size () {
		return this.items.length
	}

	clear () {
		this.items.length = 0
	}
}

export default Stack

// 通用的进制转换器
let baseConvertor = (num, base = 2) => {
	let remStack = new Stack()
	let rem
	let binaryString = ''
	let digits = '0123456789ABCDEF'

	while (num > 0) {
		rem = Math.floor(num % base)
		remStack.push(rem)
		num = Math.floor(num / base)
	}


	while(!remStack.isEmpty()) {
		binaryString += remStack.pop().toString()
	}

	return binaryString
}