摘要：
An integer is divisible by 3 if the sum of its digits is also divisible by 3. For example, 3702 is divisible by 3 and 12 (3+7+0+2) is also divisible b 阅读全文
摘要：
Problem Description A wqb-number, or B-number for short, is a non-negative integer whose decimal form contains the sub- string "13" and can be divided 阅读全文