Priority Queue Program using Heap

#include<stdio.h>
struct heapstruct
{
int capacity;
int size;
int *a;
};
typedef struct heapstruct *pq;
pq initialize(int maxa,int mindata)
{
pq h;
h=(struct heapstruct*)malloc(sizeof(struct heapstruct));
if(h==NULL)
printf(“\nOut of Space”);
h->a=(int*)malloc((maxa+1)*sizeof(int));
h->capacity=maxa;
h->size=0;
h->a[0]=mindata;
return h;
}
void insert(int x,pq h)
{
int i;
if(h->size==h->capacity)
{
printf(“\nFull”);
}
else
{
for(i=++h->size;h->a[i/2]>x;i=i/2)
{
h->a[i]=h->a[i/2];
}
h->a[i]=x;
}
}
int delmin(pq h)
{
int i,mina,lasta,child;
if(h->size==0)
{
return(h->a[0]);
}
else
{
mina=h->a[1];
lasta=h->a[h->size--];
for(i=1;i*2size;i=child)
{
child=i*2;
if(child!=h->size && h->a[child+1]a[child])
child++;
if(lasta>h->a[child])
{
h->a[i]=h->a[child];
}
else
break;
}
h->a[i]=lasta;
return mina;
}
}
void display(pq h)
{
int i;
for(i=1;isize;i++)
{
printf(“\nThe data is: %d”,h->a[i]);
}
}
void main()
{
pq h;int x,y,z,u,v;char ch;
clrscr();
printf(“\nEnter the maximum number of elements for the Priority Queue:”);
scanf(“%d”,&x);
printf(“\nEnter the minimum element :”);
scanf(“%d”,&y);
h=initialize(x,y);
menu:
printf(“\nPriority Queue”);
printf(“\n1.Insert\n2.Delete\n3.Display\n4.Exit”);
scanf(“%d”,&u);
switch(u)
{
case 1:printf(“Enter the Data:”);
scanf(“%d”,&z);
insert(z,h);
break;
case 2:v=delmin(h);
printf(“\nThe deleted element is: %d”,v);
break;
case 3:display(h);
break;
case 4:exit(0);
}
goto menu;
}

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