说明：  QBASIC的倒油问题，通过测试。设有大小不等的X，Y，Z三个无刻度的油桶，分别能够盛满油X，Y，Z(例如，X=80，Y=50，Z=30)，并约定X>Y>Z。初始时，仅X油桶盛满油，Y和Z油桶为空。要求程序寻找一种最少的分油步聚，在某个油桶中分出T升油(例如T=40)。
(QBASIC was the oil issue, to pass the test. With size ranging from X, Y, Z scale of the three non-oil drums, filled with oil, respectively, to X, Y, Z (for example, X = 80, Y = 50, Z = 30), and agreed X> Y > Z. Initially, only the X tank filled with oil, Y and Z is empty oil drums. Request procedure to find a sub-oil步聚at least, in a tank or oil in the separation of T (for example, T = 40).)