static void Game(ref Prisoner a, ref Prisoner b, int round)
{ // ^我後來發現這邊寫法有點多此一舉，物件作為引數被讀入後，本來就是傳址，不是傳值。故不用ref
switch (a.LastChoice)
{
case (Decision.COOPERATE):
if (b.LastChoice == Decision.COOPERATE)
{ // win-win
a.score += 3;
b.score += 3;
}
else
{ // b win
b.score += 5;
}
break;
case (Decision.BETRAY):
if (b.LastChoice == Decision.COOPERATE)
{ // a win
a.score += 5;
}
else
{ // Both Betray
a.score += 1;
b.score += 1;
}
break;
}
ScoreBoard(ref a, ref b, round);
Decision a_choice = a.LastChoice, b_choice = b.LastChoice;
a.Action(b_choice);
b.Action(a_choice);
}// End of void Game