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crucial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） Let the opposite winner the rest of your aquatic realm, doing away with gravel pitfalls and preserving the pristine perfection of one's acrylic haven. Dive in to the TRUVU strategy—safeguard your tank, banish alga... https://pearlaquatics.my/4-reasons-to-hire-aquarium-moving-service/