Add tit4tat c implemantation.

2 files changed, 61 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..cade429
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,2 @@
+tit4tat: tit4tat.c
+	gcc -std=c99 -Wall -o $@ $<
diff --git a/tit4tat.c b/tit4tat.c
new file mode 100644
index 0000000..fa3fe50
--- /dev/null
+++ b/tit4tat.c
@@ -0,0 +1,59 @@
+/* 
+ * 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; 
+}