规则Rules：
标准数独基础上，每条线上的数字按顺序从一端到另一端是一组等差数列。
Classic rules applied. Additionally, on each line, numbers form arithmetic sequence in order from one side to another side.
◆例题 Example
◆在线涂鸦 Draw it Online
◆在线做 Do it by CTC
◆在线做 Do it by Penpa
