北大OJ,3668到3673题源码，全部是通过代码-3070：The cows are so very silly about their dinner partners. They have organized themselves into three groups (conveniently numbered 1, 2, and 3) that insist upon dining together. The trouble starts when they line up at the

北大ACM算法中的题目，具体题目代号为1004-Peking University ACM algorithm topics, specific topics codenamed 1004

北大ACM算法中的题目，具体题目代号为1005-Peking University ACM algorithm topics, specific topics codenamed 1005