62 lines
1.0 KiB
JavaScript
62 lines
1.0 KiB
JavaScript
import "core-js/modules/es.array.push.js";
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/**
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* @class Stack
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* @util
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*/
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class Stack {
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constructor() {
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let initial = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : [];
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/**
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* Items collection.
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*
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* @type {Array}
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*/
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this.items = initial;
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}
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/**
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* Add new item or items at the back of the stack.
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*
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* @param {*} items An item to add.
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*/
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push() {
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this.items.push(...arguments);
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}
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/**
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* Remove the last element from the stack and returns it.
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*
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* @returns {*}
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*/
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pop() {
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return this.items.pop();
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}
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/**
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* Return the last element from the stack (without modification stack).
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*
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* @returns {*}
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*/
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peek() {
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return this.isEmpty() ? void 0 : this.items[this.items.length - 1];
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}
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/**
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* Check if the stack is empty.
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*
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* @returns {boolean}
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*/
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isEmpty() {
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return !this.size();
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}
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/**
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* Return number of elements in the stack.
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*
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* @returns {number}
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*/
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size() {
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return this.items.length;
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}
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}
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export default Stack; |