spoj_COINS.fsx

module Memo = 
  let empty () = new Dictionary<int64,int64>()

  let add k v (memo:Dictionary<int64,int64>) = 
    memo.[k] <- v; memo 

  let tryFind k (memo:Dictionary<int64,int64>) = 
    match memo.TryGetValue(k) with 
    | true, v -> Some(v) 
    | false,_ -> None