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） In the event of a dispute as to the id of the entrant, the approved account holder of the email address utilized to enter will be considered being the entrant. The “approved account holder” may be the organic pa... https://pearlaquatics.my/4-tips-to-follow-when-building-a-fish-pond/