task 2( ds lab 5) 3rd sem

#include<bits/stdc++.h>
using namespace std;

int heap_size;

int left(int i)
{
    return 2*i;
}
int right(int i)
{
    return 2*i+1;
}
int parent(int i)
{
    return i/2;
}
void max_heapify(int A[],int i)
{
    int l,r,largest;
    l=left(i);
    r=right(i);

    if(l<=heap_size && A[l]>A[i])
        largest=l;
    else
        largest=i;

    if(r<=heap_size && A[r]>A[largest])
        largest=r;

    if(largest!=i)
    {
        swap(A[i],A[largest]);
        max_heapify(A,largest);
    }

}
void build_max_heap(int A[],int len)
{
    for(int i=len/2;i>0;i--)
        max_heapify(A,i);
}
void heap_sort(int A[],int length)
{
    int len=length;
    build_max_heap(A,len);
    for(int i=length;i>1;i--)
    {
        swap(A[1],A[i]);
        heap_size--;
        max_heapify(A,1);
    }
}
int main()
{
    cout<<"Heap Size:";
    cin>>heap_size;
    int A[heap_size+1];
    cout<<"UNSORTED INPUT"<<endl;
    for(int i=1;i<heap_size+1;i++)
    {
        cin>>A[i];
    }
    int length=sizeof(A)/sizeof(int)-1;
    cout<<"SORTED: ";
    heap_sort(A,length);
    for(int i=1;i<length+1;i++)
    {
        cout<<A[i]<<" ";
    }
    return 0;
}