I am not able to find a blog or video which would describe how to delete an index and all its children while doing problem http://www.usaco.org/index.php?page=viewproblem2&cpid=644 . I really wanted a dsu solution. Here my implementation just have to implement delink function correctly please help. Here my submission link https://ide.usaco.guide/NX__5jD-hKhlahQ_iks