/
Stack.js
97 lines (89 loc) · 2.01 KB
/
Stack.js
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import {
deepCopy,
isFunction
} from './common/toollib'
import ArrayBasedStruct from './ArrayBasedStruct'
/**
* 栈结构
*
* @export
* @class Stack
* @extends {ArrayBasedStruct}
*/
export class Stack extends ArrayBasedStruct {
constructor() {
super()
}
/**
* 将新元素入栈
*
* @param {*} element
* @memberof Stack
*/
push(element) {
return this.__items.push(element)
}
/**
* 栈顶元素出栈
*
* @returns 栈顶元素
* @memberof Stack
*/
pop() {
return this.__items.pop()
}
/**
* 查看栈顶元素
*
* @returns 栈顶元素
* @memberof Stack
*/
peek() {
if (!this.__items.length) return undefined
return deepCopy(this.__items[this.__items.length - 1])
}
/**
*遍历栈结构
*
* @param {function} callback
* @param {boolean} [reversal=false]
* @memberof Stack
*/
traverse(callback, reversal = false) {
// 检查回调函数
if (!isFunction(callback)) return
var items = this.getItems(this.__items)
var from = reversal ? items.length - 1 : 0
var to = reversal ? 0 : items.length - 1
// 循环条件
var loopCondition = function (current) {
if (reversal) {
return current >= to
} else {
return current <= to
}
}
// 游标前进
var stepIn = function (current) {
if (reversal) {
return current - 1
} else {
return current + 1
}
}
// 进行遍历
for (var index = from; loopCondition(index); index = stepIn(index)) {
var element = items[index];
callback(element, index)
}
}
/**
* 转为字符串
*
* @returns
* @memberof Stack
*/
toString() {
return this.__items.map(element => element.toString()).join(' ')
}
}