画宫锯齿 Tripod

填入1~N，使得每行、列、宫内数字不重复。宫被隐藏了，所有的宫线条的交叉点都被画出，此外不存在十字形的交叉点。

Write 1~N to make numbers no repeated in each Row, Column and Box. The Box are hidden, all points where three Box lines meet are given, and there won't be a point for four lines meeting.

Pick the pic from http://cross-plus-a.com

赛事频率 极低

国内部分图书及国外部分数独软件有涉及。