max_heapify(a,n,i)
largest=i;
temp=-1;
while(lagest<=n)
then l=2*largest;
r=2*largest+1;
if(l<=n and a[l]>a[largest])
then largest=l;
if(r<=n and a[r]>a[largest])
then largest=r;
if(largest!=temp)
then a[laegest]<->a[temp];
else
break;