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 can't connect with the server for this app or Web page right now. There may be far too much visitors or a configuration error. Check out once again afterwards, or Make contact with the application or Web page ... https://pearlaquatics.my/product/sobo4x2x2/