We hope that no difficulties, misunderstanding and "wtf am i asked to do" thoughts ruined your fun!
Problem A: Nash equilibrium
Problem B: DAG
Problem C: Segment tree or Fenwick?
Problem D: Dijkstra
Problem E: Amazing bitset
In problems F, G and J we don't mention in the editorial that we assume you to have parsed the statement into a convenient programming-friendly format.
Problem F: Keep talking and nobody explodes -- easy
Problem G: Keep talking and nobody explodes -- medium
Problem H: Who needs suffix structures?
Problem I: Deja vu
Problem J: Keep talking and nobody explodes -- hard
