How do I transform an IF statement with 2 variables onto a switch function using C?

Question

I have an IF-statement that I want to transform into a Switch-statement... But it has 2 variables! Is it possible to do it on C?

It is a rock, paper, scissors game:

Answer 1

The too-clever-by-half solution:

enum Play { Rock = 0, Paper = 1, Scissors = 2 };
enum Outcome { Tie = 0, P1Win = 1, P2Win = 2 };

enum Play parseMove(char input) {
    switch (input) {
        case 'R': return Rock;
        case 'P': return Paper;
        case 'S': return Scissors;
        default: /* invalid input */;
    }
}

enum Outcome gameResult(enum Play p1, enum Play p2) {
    return (3 + p1 - p2)%3;
}

...

switch(gameResult(parseMove(play1), parseMove(play2))) {
    case Tie: printf("Tie!\n");
    case P1Win: printf("Player 1 wins!\n");
    case P2Win: printf("Player 2 wins!\n");
}