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important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） Reside plants tend to be more than simply decorative components in a freshwater aquarium. They add to oxygenation, assistance manage drinking water good quality, and provide natural habitats for fish. 查看 時間:... https://pearlaquatics.my/how-to-build-a-fish-pond-or-a-garden-pond-at-home/