雾胡的博客

题目： There are n pictures delivered for the new exhibition. The i-th painting has beauty ai. We know that a visitor becomes happy every time he passes from a painting to a more beautiful one. We are al...

题目： We all know that a superhero can transform to certain other superheroes. But not all Superheroes can transform to any other superhero. A superhero with name s can transform to another superhero wi...