1 files changed, 173 insertions, 0 deletions
diff --git a/kpat/freecell-solver/pqueue.c b/kpat/freecell-solver/pqueue.c
new file mode 100644
index 00000000..086cce96
--- /dev/null
+++ b/kpat/freecell-solver/pqueue.c
@@ -0,0 +1,173 @@
+/*
+    pqueue.c - implementation of a priority queue by using a binary heap.
+
+    Originally written by Justin-Heyes Jones
+    Modified by Shlomi Fish, 2000
+
+    This file is in the public domain (it's uncopyrighted).
+
+    Check out Justin-Heyes Jones' A* page from which this code has
+    originated:
+        http://www.geocities.com/jheyesjones/astar.html
+  */
+
+/* manage a priority queue as a heap
+   the heap is implemented as a fixed size array of pointers to your data */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "jhjtypes.h"
+
+#include "pqueue.h"
+
+#ifdef DMALLOC
+#include "dmalloc.h"
+#endif
+
+#define TRUE 1
+#define FALSE 0
+
+/* initialise the priority queue with a maximum size of maxelements. maxrating is the highest or lowest value of an
+   entry in the pqueue depending on whether it is ascending or descending respectively. Finally the bool32 tells you whether
+   the list is sorted ascending or descending... */
+
+void freecell_solver_PQueueInitialise(
+    PQUEUE *pq,
+    int32 MaxElements
+    )
+{
+    pq->MaxSize = MaxElements;
+
+    pq->CurrentSize = 0;
+
+    pq->Elements = (pq_element_t*) malloc( sizeof( pq_element_t ) * (MaxElements + 1) );
+
+    if( pq->Elements == NULL )
+    {
+        printf( "Memory alloc failed!\n" );
+    }
+}
+
+/* join a priority queue
+   returns TRUE if successful, FALSE if fails. (You fail by filling the pqueue.)
+   PGetRating is a function which returns the rating of the item you're adding for sorting purposes */
+
+int freecell_solver_PQueuePush( PQUEUE *pq, void *item, pq_rating_t r)
+{
+    uint32 i;
+    pq_element_t * Elements = pq->Elements;
+
+    int32 CurrentSize = pq->CurrentSize;
+
+    if (CurrentSize == pq->MaxSize )
+    {
+        int new_size;
+        new_size = pq->MaxSize + 256;
+        pq->Elements = Elements = (pq_element_t *)realloc( Elements, sizeof(pq_element_t) * (new_size+1));
+        pq->MaxSize = new_size;
+    }
+
+    {
+        /* set i to the first unused element and increment CurrentSize */
+
+        i = (++CurrentSize);
+
+        /* while the parent of the space we're putting the new node into is worse than
+           our new node, swap the space with the worse node. We keep doing that until we
+           get to a worse node or until we get to the top
+
+           note that we also can sort so that the minimum elements bubble up so we need to loops
+           with the comparison operator flipped... */
+
+        {
+
+            while( ( i==PQ_FIRST_ENTRY ?
+                     (PQUEUE_MaxRating) /* return biggest possible rating if first element */
+                     :
+                     (PGetRating(Elements[ PQ_PARENT_INDEX(i) ]) )
+                   )
+                   < r
+                 )
+            {
+                Elements[ i ] = Elements[ PQ_PARENT_INDEX(i) ];
+
+                i = PQ_PARENT_INDEX(i);
+            }
+        }
+
+        /* then add the element at the space we created. */
+        Elements[i].item = item;
+        Elements[i].rating = r;
+    }
+
+    pq->CurrentSize = CurrentSize;
+
+    return TRUE;
+
+}
+
+#define PQueueIsEmpty(pq) ((pq)->CurrentSize == 0)
+
+/* free up memory for pqueue */
+void freecell_solver_PQueueFree( PQUEUE *pq )
+{
+    free( pq->Elements );
+}
+
+/* remove the first node from the pqueue and provide a pointer to it */
+
+void *freecell_solver_PQueuePop( PQUEUE *pq)
+{
+    int32 i;
+    int32 child;
+    pq_element_t * Elements = pq->Elements;
+    int32 CurrentSize = pq->CurrentSize;
+
+    pq_element_t pMaxElement;
+    pq_element_t pLastElement;
+
+    if( PQueueIsEmpty( pq ) )
+    {
+        return NULL;
+    }
+
+    pMaxElement = Elements[PQ_FIRST_ENTRY];
+
+    /* get pointer to last element in tree */
+    pLastElement = Elements[ CurrentSize-- ];
+
+    {
+
+        /* code to pop an element from an ascending (top to bottom) pqueue */
+
+        /*  UNTESTED */
+
+        for( i=PQ_FIRST_ENTRY; (child = PQ_LEFT_CHILD_INDEX(i)) <= CurrentSize; i=child )
+        {
+            /* set child to the smaller of the two children... */
+
+            if( (child != CurrentSize) &&
+                (PGetRating(Elements[child + 1]) > PGetRating(Elements[child])) )
+            {
+                child ++;
+            }
+
+            if( PGetRating( pLastElement ) < PGetRating( Elements[ child ] ) )
+            {
+                Elements[ i ] = Elements[ child ];
+            }
+            else
+            {
+                break;
+            }
+        }
+    }
+
+    Elements[i] = pLastElement;
+    pq->CurrentSize = CurrentSize;
+
+    return pMaxElement.item;
+}
+
+