回複:回複:回複:Problem 6

來源: 2009-07-28 09:14:51 [舊帖] [給我悄悄話] 本文已被閱讀:

then think about a = {1, 3, 2} and M = {3, 4}

a' = {1, 3}, M' = {3} is a valid solution for n = 2. However, 4 = 1 + 3, and there is no way to fix it by changing the order of 3 and 2.