I need help to solve this problem

given a tree with N nodes and K robots you want minimize the total distance needed to visit each node at least once by one robot if all robots started at node i.

robots are allowed to stop at any node and don't move.

for each node i from 1 to N output the answer if all robots started from node i, more details is in the link above.

N<=15,000 K<=30

thanks..