Merge branch 'c-agents'

[progcomp10.git] / src / link / C / agents / c_wash.c

diff --git a/src/link/C/agents/c_wash.c b/src/link/C/agents/c_wash.c
new file mode 100644 (file)
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+++ b/src/link/C/agents/c_wash.c
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+/*
+ *  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>
+#include <string.h>
+
+/* Implement the wash agent, 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
+   (note that this is only a guess, not an upper limit. Do *not* take it as 
+   gospel on the number of agents you're going to see. */
+#define NUMBEROFAGENTSGUESS 100
+
+/* data for each instance of my agent */
+typedef struct {
+       /* The name of the n-th foe who has beaten us */
+       char (*defeatingFoes)[MAXAGENTNAMELEN];
+
+       /* The length of the array, and how far we are along it */
+       size_t foesLen;
+       unsigned int foesCount;
+} wash_data;
+
+
+/* an internal function - have I lost to a given foe? */
+int haveLostTo( wash_data * me, char * foeName ) {
+    
+       int foe;
+    
+    /* check every foe we know to have defeated us */
+    for (foe=0; foe<me->foesCount; foe++) {
+        if (strncmp( me->defeatingFoes[foe], foeName, MAXAGENTNAMELEN) == 0) {
+            //debugmsg( "%d\thaveLostTo( %s ) -> Yes\n", me, foeName );
+            return 1;
+        }
+    }
+    
+    /* this foe not found */
+    return 0;
+}
+
+/* set up myself */
+void * Initialise( char * myName ) {
+       wash_data * me = malloc( sizeof( wash_data ) );
+       
+       me->defeatingFoes = calloc( NUMBEROFAGENTSGUESS, sizeof( MAXAGENTNAMELEN*sizeof(char) ) );
+       me->foesLen = NUMBEROFAGENTSGUESS;
+    me->foesCount = 0;
+       
+       return (void *) me;
+}
+
+/* Attack */
+ATTACKTYPE Attack( void * this, char * foeName ) {
+       wash_data * me = (wash_data *)this;
+    
+       ATTACKTYPE attack;
+       
+       attack.realAttack =  RandomAttack();
+       
+    /* have I lost to this foe? */
+    if ( haveLostTo(me, foeName) ) {
+        /* Assume they are lying  */
+        switch (attack.realAttack) {
+            case rock:
+                attack.promisedAttack = scissors;
+                break;
+            case paper:
+                attack.promisedAttack = rock;
+                break;
+            default: /* attack = scissors */
+                attack.promisedAttack = paper;
+                break;
+        }
+    } else {
+        /* be nice! */
+        attack.promisedAttack = attack.realAttack;
+    }
+
+       
+       return attack;
+}
+
+/* defend */
+ITEMTYPE Defend( void * this, char * foeName, ITEMTYPE foePromisedAttack ) {
+       wash_data * me = (wash_data *)this;
+       
+       ITEMTYPE defence;
+       
+    if (haveLostTo(me, foeName)) {
+        /* They've screwed us in the past, assume they're lying and go for the
+           kill. */
+        switch (foePromisedAttack) {
+            case rock:
+                defence = scissors;
+                break;
+            case paper:
+                defence = rock;
+                break;
+            default:
+                defence = paper;
+                break;
+        }
+    } else {
+        /* be nice! */
+        defence = foePromisedAttack;
+    }
+
+    return defence;
+}
+
+/* This is so much less fun in C */
+void Results( void * this, char * foeName, int isInstigatedByYou, 
+                        RESULTTYPE winner, ITEMTYPE attItem, ITEMTYPE defItem, 
+                        ITEMTYPE bluffItem, int pointDelta ) {
+       
+    wash_data * me = (wash_data *)this;
+       
+       int foe;
+    
+    /* figure out if we lost, which is the only thing we care about
+       if we didn't, move on. */
+    if ((winner == tie) || 
+        (winner==attacker && isInstigatedByYou) ||
+        (winner==defender && !isInstigatedByYou) ) return;
+    
+    //fprintf( stderr, "%d\tsaving loss from %s\n", me, foeName );
+    
+    /* if we've already lost the foe, don't store again */
+    for (foe=0; foe<me->foesCount; foe++) {
+        if (strncmp( me->defeatingFoes[foe], foeName, MAXAGENTNAMELEN ) == 0) {
+            /* we've found it! */
+            return;
+        }
+    }
+    
+    /* we haven't found the foe. add it, expanding the array if needed */
+    if (me->foesCount==me->foesLen) {
+        /* double the array size. This should error check, but doesn't */
+        me->defeatingFoes = realloc( me->defeatingFoes, 
+                                            me->foesLen*2*sizeof( MAXAGENTNAMELEN*sizeof(char) ) );
+        me->foesLen *= 2;
+    }
+    
+    strncpy( me->defeatingFoes[me->foesCount], foeName, MAXAGENTNAMELEN );
+    me->foesCount++;
+    
+    return;
+}
+
+/* Cleanup */
+void Cleanup( void * this ) {
+       wash_data * me = (wash_data *) this;
+       free(me->defeatingFoes);
+       free(me);
+}
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