回复：回复：回复：印尼奥赛题（1星）to aceonriver

来源: 于 2009-11-05 13:45:53 [旧帖] [给我悄悄话] 本文已被阅读：次

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