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essential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） All logos are possibly the house of Central Backyard & Pet Business, its subsidiaries, divisions, affiliated and/or linked companies or even the house in their respective homeowners. 排序: 發帖時間 Commemorates ... https://pearlaquatics.my/7-ways-to-keep-fish-pond-clean-healthy/