Queue

JavaScriptのArray.shiftメソッドは処理にO(n)掛かるため、Queueを用いる際は工夫する必要がある

詳しくは参照先記事を参考

参照先

code: Queue.js

class Queue {

constructor() {

this._in = []

this._out = [];

}

get length() {

return this._in.length + this._out.length;

}

_fix() {

this._out = this._in.reverse().concat(this._out);

this._in = [];

}

toArray() {

this._fix();

return this._out.slice().reverse();

}

push(value) { this._in.push(value); }

shift() {

if (this._out.length === 0) this._fix();

return this._out.pop();

}

get exist() { return this.length > 0; }

get empty() { return this.length == 0; }

}