void buildHuffmanTree() {
//if pq is empty then nothing to do
if(empty()){
return;
}
//while queue has more than 1 node
//NOTE: I wrote a size() function for the pq to make this easy
while(size() > 1)
{
//grab 2 smallest nodes p1 and p2 from pq
node *p1 = pqmindelete();
node *p2 = pqmindelete();
//create new node that is sum of p1 and p2 frequencies
//create new parent
node *p = getNode(p1->info + p2->info);
//set p to be parent of p1 and p2
p1->parent =p;
p2 -> parent =p;
//setleft p1
p1->left = p1;
//setright p2
p2->right = p2;
//put p in pq
pqinsert(p);
//last node in pq is the root so get it from pq and assign to root
}
root = pqmindelete();
}
struct pqueue *
naive_sph_range(struct kd_point *pointlist, unsigned int npoints, float *p,
float *range)
{
struct pqueue *res;
struct resItem *point;
float dsq;
unsigned int i;
if ((res = pqinit(NULL, 1)) == NULL) {
fprintf(stderr, "Could not allocate memory for result queue\n.");
return NULL;
}
for(i=0; i<npoints; i++) {
if ((dsq = kd_sph_dist_sq(pointlist[i].point, p)) < *range) {
if ((point = kd_malloc(sizeof(struct resItem), "naive_qnearest: "))
== NULL)
return NULL;
if ((point->node = kd_allocNode(pointlist, i,
/* 2 dummies */
pointlist[i].point,
pointlist[i].point,
-1, 2)) == NULL)
return NULL;
point->dist_sq = dsq;
pqinsert(res, point);
}
}
return res;
}
void buildQueue() {
int i;
for(i = 0; i < NUMSYMBOLS; i++) {
if(frequency[i] > 0) {
node * n = getNode(frequency[i]);
position[i] = n;
pqinsert(n);
}
}
}
main()
{
int ch,e,temp,old;
pq.front=pq.rear=SIZE-1;
while(1)
{
system("cls");
char ch1='N';
printf("\n\n\nPriority Queue Implementation\n\n\n");
printf("1. Insert Elements\n");
printf("2. Delete Smallest Element\n");
printf("3. Delete Largest Element\n");
printf("4. Display Elements\n");
printf("5. Quit\n\n");
printf("Enter Choice:");
scanf("%d",&ch);
switch(ch)
{
case 1:
printf("\nEnter Element:");
scanf("%d",&temp);
pqinsert(&pq,temp);
break;
case 2:
fflush(stdin);
if(emptys(&pq))
{
printf("\nUnderflow");
getchar();
break;
}
if(pq.front==SIZE-1)
printf("\nDelete %d (Y/N)?", pq.elements[0]);
else
printf("\nDelete %d (Y/N)?", pq.elements[pq.front+1]);
scanf("%c", &ch);
if(ch=='Y' || ch=='y')
{
temp=pqmindelete(&pq);
printf("\n%d Deleted !",temp);
fflush(stdin);
getchar();
}
break;
case 3:
fflush(stdin);
if(emptys(&pq))
{
printf("\nUnderflow");
getchar();
break;
}
printf("\nDelete %d (Y/N)?", pq.elements[pq.rear]);
scanf("%c", &ch);
if(ch=='Y' || ch=='y')
{
temp=pqmaxdelete(&pq);
printf("\n%d Deleted !",temp);
fflush(stdin);
getchar();
}
break;
case 4:
fflush(stdin);
if(pq.front==pq.rear)
{
printf("\nPriority Queue Empty");
getchar();
break;
}
old=pq.front;
printf("\nPriority Queue List: ");
while(pq.front!=pq.rear)
{
if(pq.front==SIZE-1)
pq.front=0;
else
pq.front++;
printf("%d->",pq.elements[pq.front]);
}
getchar();
pq.front=old;
break;
case 5: exit(1);
default: printf("\nIncorrect Choice");
fflush(stdin);
getchar();
}
}
}
