hdu1828 Picture(线段树+离散化+扫描线+基础周长并模板)两种方法

A number of rectangular posters, photographs and other pictures of the same shape are pasted on a wall. Their sides are all vertical or horizontal. Each rectangle can be partially or totally covered by the others. The length of the boundary of the union of all rectangles is called the perimeter. A number of rectangular posters, photographs an