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 crops tend to be more than just decorative components within a freshwater aquarium. They lead to oxygenation, aid sustain water high quality, and provide all-natural habitats for fish. 查看 時間: 全部時間... https://pearlaquatics.my/tips-to-follow-when-installing-a-fish-tank-malaysia/