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） Reside vegetation tend to be more than just attractive elements within a freshwater aquarium. They add to oxygenation, help preserve water quality, and supply pure habitats for fish. 回復/查看 一天 ● हर महीने पैसे... https://pearlaquatics.my/what-should-be-your-first-steps-to-set-up-an-aquarium/