Hi guys, i participated srm717 last night, and submitted q1, here is my idea (but failed in system test, i have no idea)
First we know there is one and only one solution, which makes the difficulty of this problem locate on constructing the graph.
So i came up with a greedy idea:
(1) we sort S[] from small to big, then we bruteforce i from 1 -> n
(2) we try to choose some nodes to be connected with node i, the nodes should satisfy that
they haven't been connected with i yet
their outdegree should be as small as possible
then i passed all the examples but got failed in system test.. i am a bit curious
btw the contest is not active therefore i can't see the test data
Thanks guys :)