gistfile1.cs

// Store a deck in a bit array by the following algorithm:
// value := pick[0];
// value = value * 51 + second pick
// value = value * 50 + third pick
// ..
// value = value * 1 + 52nd pick
// The first pick is pick[0]
BigInt StoreDeck(params int[] picks) {
  BigInt value = pick[0];
  for(int i = 1; i < picks.Length; i++) {
    value *= (picks.Length - i) + 1;
    value += picks[i];
  }
  return value;
}