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） All trademarks are either the house of Central Back garden & Pet Organization, its subsidiaries, divisions, affiliated and/or linked businesses or even the residence in their respective owners. ● पोस्ट, स्टोरीज़, ... https://pearlaquatics.my/why-should-you-focus-on-pond-cleaning/