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/* 
 * Copyright (c) 2012 Jan Klemkow <j.klemkow@wemelug.de> 
 * Copyright (c) 2012 Benjamin Franzke <benjaminfranzke@googlemail.com> 
 * 
 * Permission to use, copy, modify, and distribute this software for any 
 * purpose with or without fee is hereby granted, provided that the above 
 * copyright notice and this permission notice appear in all copies. 
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 
 */ 

#include <stdio.h> 
#include <unistd.h> 
#include <stdlib.h> 

enum {COORPERATION, DEFECTION}; 

int pay(int a, int b) 
{ 
        if (a == COORPERATION && b == DEFECTION)    return 1; 
        if (a == DEFECTION    && b == DEFECTION)    return 2; 
        if (a == COORPERATION && b == COORPERATION) return 3; 
        if (a == DEFECTION    && b == COORPERATION) return 4; 

        exit(EXIT_FAILURE); 
} 

int main(int argc, char **argv) 
{ 
        int a_payment = 0, b_payment = 0; 
        int a, b, a_old = -1; 

        for (;;) { 
                /* human input */ 
                a = getc(stdin); 
                fpurge(stdin); 
                a = (a == 'c') ? COORPERATION : DEFECTION; 

                /* computer rules */ 
                b =  (a_old == -1) ? COORPERATION : a_old; 

                a_payment += pay(a, b); 
                b_payment += pay(b, a); 

                printf("A: %d Euro\tB: %d Euro\t\t\tA: %d\tB: %d\n", 
                        pay(a, b), pay(b, a), a_payment, b_payment); 

                /* save the last human decision */ 
                a_old = a; 
        } 

        return EXIT_SUCCESS; 
}