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vital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） Are living plants tend to be more than just ornamental aspects in a freshwater aquarium. They contribute to oxygenation, support retain drinking water good quality, and supply purely natural habitats for fish. चैनल ... https://pearlaquatics.my/how-to-find-the-best-aquarium-cleaner/