再用n2的时间（两重循环）枚举d-c，并将b-c的值作为键，在Hash数组中查找是否存在。如果能找到critical相同的node点，则找到了一组满足 d-c = a+b的值。（注意检查a b c d 四个数不重复） We will not hook up with the server for this app or Web-site right now. There could possibly be a lot of traffic or maybe a configuration error. Try out once again later on, or Get hold of the app or Web https://pearlaquatics.my/routine-maintenance/