# HG changeset patch
# User Sean <seanhalle@yahoo.com>
# Date 1337279719 -7200
# Node ID 0de14128ff68b25602854a57dcede889d0529509
# Parent  ee94893d28432f306a082548d747c03105cbb653
comments added for Stefan, and formatting changes

diff -r ee94893d2843 -r 0de14128ff68 PriorityQueue.c
--- a/PriorityQueue.c	Mon May 14 16:24:26 2012 -0700
+++ b/PriorityQueue.c	Thu May 17 20:35:19 2012 +0200
@@ -11,6 +11,7 @@
 
 #include "PriorityQueue.h"
 
+//Stefan: nice use of macros  : )
 #define left(i) 2*i
 #define right(i) 2*i+1
 #define parent(i) i/2
@@ -27,16 +28,19 @@
 	
 }
 
-bool increaseKey (PrioQueueStruc *Q, int i, int key) {
-	if (key < Q->data[i].key) return false; // increasing not possible
+bool 
+increaseKey( PrioQueueStruc *Q, int i, int key ) 
+ {
+   if( key < Q->data[i].key ) 
+       return false; // increasing not possible
 
-	Q->data[i].key= key;
-	while (i>0 && Q->data[parent(i)].key < Q->data[i].key) {
-		swap(Q,i,parent(i));
-		i= parent(i);
-	}	
-	return true;
-}
+   Q->data[i].key= key;
+   while( i > 0 && Q->data[parent(i)].key < Q->data[i].key )
+    { swap( Q, i, parent(i) );
+      i = parent(i);
+    }
+   return true;
+ }
 
 void heapify (PrioQueueStruc *Q, int i) {
 	int largest;
@@ -52,32 +56,40 @@
 	}
 }
 
-void enlargePrioQ (PrioQueueStruc *Q)  {
-	size_t oldSize, newSize;
-	heapNode *oldData,*newData;
+void 
+enlargePrioQ( PrioQueueStruc *Q )
+ { size_t oldSize, newSize;
+   heapNode *oldData,*newData;
 
-	oldSize= Q->size;
-	newSize= 2*oldSize;
+   oldSize = Q->size;
+   newSize = 2*oldSize;
 
-	Q->maxSize= newSize;
-	newData= VMS_PI__malloc(Q->maxSize*sizeof(heapNode));
-	oldData= Q->data;
+   Q->maxSize = newSize;
+   newData = VMS_PI__malloc( Q->maxSize * sizeof(heapNode) );
+   oldData = Q->data;
 
-	memcpy(newData,oldData,Q->maxSize*sizeof(heapNode));
-	Q->data= newData;
+   //Stefan: should this be Q->maxSize, or oldSize?  Copying old data into
+   // new array, so oldSize is the amount of data.. does the data need to
+   // be re-arranged to make sure it still has heap invariant within the new
+   // size?
+   memcpy( newData, oldData, Q->maxSize * sizeof(heapNode) );
+   Q->data = newData;
 
-	VMS_PI__free(oldData);
-}
+   VMS_PI__free(oldData);
+ }
 
 
-PrioQueueStruc* makePrioQ () {
-	PrioQueueStruc *retQ;
-	retQ= VMS_int__malloc(sizeof(PrioQueueStruc));
-	retQ->maxSize= 1024;
-	retQ->data= VMS_int__malloc(retQ->maxSize*sizeof(heapNode));
-	retQ->size= 0;
-	return retQ;
-}
+PrioQueueStruc * 
+makePrioQ() 
+ { PrioQueueStruc *newQ;
+ 
+   newQ= VMS_int__malloc( sizeof(PrioQueueStruc) );
+   newQ->maxSize= 1024;
+   newQ->data= VMS_int__malloc( newQ->maxSize * sizeof(heapNode) );
+   newQ->size= 0;
+   
+   return newQ;
+ }
 
 void* getFirstPrioQ (PrioQueueStruc *Q) {
 	return Q->data[0].val;
@@ -93,17 +105,19 @@
 		heapify(Q,0);
 	}	
 	return max;
-}
+ }
 
-bool insertPrioQ (void *val, int key, PrioQueueStruc *Q) {
-	if (Q->size == Q->maxSize) enlargePrioQ(Q);
+bool
+insertPrioQ (void *val, int key, PrioQueueStruc *Q) 
+ {
+   if( Q->size == Q->maxSize ) enlargePrioQ(Q);
 
-	Q->size++;
-	Q->data[Q->size-1].key= INT_MIN;
-	Q->data[Q->size-1].val= val;
+   Q->size++;
+   Q->data[Q->size-1].key= INT_MIN;
+   Q->data[Q->size-1].val= val;
 
-	return increaseKey(Q,Q->size-1,key);
-}
+   return increaseKey(Q, Q->size-1, key);
+ }
 
 void printPrioQ (PrioQueueStruc *Q) {
 	int i;