72 lines
1.5 KiB
TypeScript
72 lines
1.5 KiB
TypeScript
/**
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* 泛型栈
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*
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* @author caizhitao
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* @created 2020-11-28 09:49:52
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*/
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export default class Stack<T> {
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private _array: Array<T>;
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constructor() {
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this._array = new Array<T>();
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}
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/**
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* 往栈加入新的元素
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*
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* @param element 待加入元素
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*/
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push(element: T): boolean {
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if (element == null) {
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return false;
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}
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// adds one or more elements to the end of an array and returns the new length of the array.
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this._array.push(element);
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return true;
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}
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/**
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* 返回栈尾部元素，并从栈中移除
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*
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* @returns 取出的元素 或者 undefined(队列中没有元素时)
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*/
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pop(): T {
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// removes the last element from an array and returns that element. This method changes the length of the array.
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return this._array.pop();
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}
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/**
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* 返回栈头部元素，不会从栈中移除
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*/
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first(): T {
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return this.isEmpty() ? null : this._array[0];
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}
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/**
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* 返回栈尾部元素，不会从栈中移除
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*/
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last(): T {
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return this.isEmpty() ? null : this._array[this.size() - 1];
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}
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/**
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* 放回当前栈大小
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*/
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size(): number {
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return this._array.length;
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}
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/**
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* 当前栈是否为空
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*/
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isEmpty(): boolean {
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return this.size() === 0;
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}
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/**
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* 清空栈，栈清空之后不能再继续使用
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*/
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clear() {
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delete this._array;
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}
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}
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