How can I solve this problem SEQUENCE LAND from INOI 13? https://www.codechef.com/IOIPRAC/problems/INOI1302

My initial approach was to check every possible pair of relatives and then do a dfs on the king and find the size of the graph. But to check for relatives it took me O(n^4) time - http://ideone.com/6ZhqNB . To speed it up I tried using binary search O(n^3 logn) http://ideone.com/oV2tHw but that doesn’t seem to work for some reason can anybody find out the problem in my binary search code or suggest a better way to solve this problem?