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） Regular testing and adjustment of salinity amounts are important with the well-getting of the maritime everyday living. Normally utilize a reliable hydrometer or refractometer to evaluate salinity properly. 排序... https://pearlaquatics.my/category/pearl-aquatics/page/2/