From: Daniel Axtens <dja@ucc.asn.au>
Date: Thu, 22 Apr 2010 16:57:58 +0000 (+0800)
Subject: Don't forget Frenchie, he'll turn against you
X-Git-Tag: v01~28
X-Git-Url: https://git.ucc.asn.au/?p=progcomp10.git;a=commitdiff_plain;h=4597b27a44522a5c2785cc23029435f44f60ea55

Don't forget Frenchie, he'll turn against you
---

diff --git a/link/C/c-link-lib/agents/c-frechie.c b/link/C/c-link-lib/agents/c-frechie.c
new file mode 100644
index 0000000..ed2ba09
--- /dev/null
+++ b/link/C/c-link-lib/agents/c-frechie.c
@@ -0,0 +1,104 @@
+/*
+ *  c-frechie.c
+ *  c-link-lib
+ *
+ *  Created by Daniel Axtens on 22/04/10.
+ *  Licensed under an MIT-style license: see the LICENSE file for details.
+ *
+ */
+
+#include <c_link.h>
+#include <stdlib.h>
+
+/* Implement the frenchie bot, that is by default nice but will 
+   permanently turn against any agent that betrays it.
+   This is trickier in C than in any other language, for a number of reasons:
+     - there's no classes in C, so we can't just write a generic learning agent
+       and subclass it.
+     - your agent has no idea how many agents it's going to battle, or how many
+       battles it is going to fight, so you've got to do dynamic memory allocation.
+        (anyone who tries to read the source of the supervisor to find out is liable
+         to have their program break unexpectedly)
+ */
+
+/* To simplify things, we just look at whether we have lost to a particular agent.
+   Unlike in the Python version, we don't keep a generic list
+   This is also done in a inefficient (O(bot-cout)) way.
+   Implementing a faster version is left as an exercise to the DSA student. */
+
+/* Our guess at the number of agents I'm going to fight in my lifetime */
+#define NUMBEROFAGENTSGUESS 100
+
+/* The name of the n-th foe we've seen, as well as a 0/1 have we lost to them */
+char foesNames[][MAXFOENAMELEN] = NULL;
+int haveLostToFoe[] = NULL;
+
+/* The length of the array, and how far we are along it */
+size_t foesLen = 0;
+unsigned int foesCount = 0;
+
+
+ATTACKTYPE Attack( char * foe_name ) {
+	ATTACKTYPE attack;
+	
+	attack.realAttack =  RandomAttack();
+	
+	/* Here we choose the thing that will hurt them if they go for the kill */
+	switch (attack.realAttack) {
+		case rock:
+			result.promisedAttack = paper;
+			break;
+		case paper:
+			result.promisedAttack = scissors;
+			break;
+		default: /* attack = scissors */
+			result.promisedAttack = rock;
+			break;
+	}
+	return attack;
+}
+
+/* Here we assume they are lying, trying to kill us. And we try to kill them. */
+ITEMTYPE Defend( char * foeName, ITEMTYPE foePromisedAttack ) {
+	ITEMTYPE defence;
+	switch (foePromisedAttack) {
+		case rock:
+			defence = scissors;
+			break;
+		case paper:
+			defence = rock;
+			break;
+		default:
+			defence = paper;
+			break;
+	}
+}
+
+/* This is so much less fun in C */
+void Results( char * foeName, int isInstigatedByYou, ITEMTYPE yourItem, 
+			 ITEMTYPE theirItem, ITEMTYPE promisedItem) {
+	
+    int foe;
+    
+    /* check to see if we've initialised our arrays */
+	if (foesNames == NULL) {
+        foesNames = calloc( NUMBEROFAGENTSGUESS, sizeof( foesNames[0] ) );
+        haveLostToFoe = calloc( NUMBEROFAGENTSGUESS, sizeof( haveLostToFoe[0] ) );
+        foesLen = NUMBEROFAGENTSGUESS;
+    }
+    
+    /* figure out if we lost, which is the only thing we care about
+       if we didn't, move on. */
+    if (RESULTOF[yourItem][theirItem] != lose) return;
+    
+    /* try and find existing foe */
+    
+    return;
+}
+
+/* same for Cleanup() */
+
+void Cleanup() {
+	free(foesNames);
+    free(haveLostToFoe);
+}
\ No newline at end of file