回複：回複：回複：印尼奧賽題（1星）to aceonriver

來源: 於 2009-11-05 13:45:53 [舊帖] [給我悄悄話] 本文已被閱讀：次

for even divisors, we need to count 2,4,6,8 etc. and for odd divisors, need to count 3,6,21 etc.