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) Dwell plants are more than simply attractive elements in the freshwater aquarium. They lead to oxygenation, aid sustain drinking water excellent, and supply organic habitats for fish. Given that fish are not able ... https://pearlaquatics.my/nitrogen-cycle/