#include <stdio.h>
#include <stdlib.h>	// for rand and srand
#include <time.h>		// for time
#include <string.h>	// memset and strcmp

struct player {
	int choice;	// rock, paper or scissors
	int wins;
	int losses;
	int ties;
};

char *choices[] = { "rock", "paper", "scissors" };

void roshambo (struct player p[2]) {
	int win_matrix[3][3] = {
		/* rock   paper   scissors */
		{   -1,    1,        0 },	/* rock */
		{   0,     -1,       1 },	/* paper */
		{   1,     0,       -1 }	/* scissors */
	};
	int winner,loser;

	winner = win_matrix[p[0].choice][p[1].choice];
	if (winner == -1) {
		printf ("It's a tie!  Human: %s  Computer: %s\n",
				choices[p[0].choice], choices[p[1].choice]);
		p[0].ties++;
		p[1].ties++;
		return;
	}
	
	if (winner == 0)  loser = 1;
	else loser = 0;

	printf ("Human: %s  Computer: %s  Winner: %s\n",
			choices[p[0].choice], choices[p[1].choice],
			winner == 0 ? "Human" : "Computer");
	p[winner].wins++;
	p[loser].losses++;
}

int main () {
	struct player player[2];
	char buffer[16];	// Input buffer
	int i;

	/* Set player values to all 0, the quick way */
	memset (player, 0, sizeof(struct player) * 2);

	srand(time(NULL));

	while (printf ("Enter choice: ") && scanf("%15s",buffer)) {
		for (i = 0; i < 3; ++i) {
			if (!strcmp (choices[i], buffer)) {
				player[0].choice = i;
				break;
			}
		}
		if (i == 3) {
			printf ("Invalid choice.\n");
			continue;
		}

		player[1].choice = rand() % 3;
		
		roshambo (player);
		printf ("Score:\nHuman: %d/%d/%d  Computer: %d/%d/%d\n",
				player[0].wins, player[0].losses, player[0].ties,
				player[1].wins, player[1].losses, player[1].ties);
	}

	return 0;
}