Heap Sort

Heap Sort

#include<stdio.h>
#include<conio.h>

void create(int []);
void down_adjust(int [],int);

void main()
{
  int heap[30],n,i,last,temp;
  clrscr();
  printf("Enter no. of elements:");
  scanf("%d",&n);
  printf("\nEnter elements:");
  for(i=1;i<=n;i++)
    scanf("%d",&heap[i]);
 
  //create a heap
  heap[0]=n;
  create(heap);
 
  //sorting
  while(heap[0] > 1)
  {
    //swap heap[1] and heap[last]
    last=heap[0];
    temp=heap[1];
    heap[1]=heap[last];
    heap[last]=temp;
    heap[0]--;
    down_adjust(heap,1);
  }

  //print sorted data
  printf("\nArray after sorting:\n");
  for(i=1;i<=n;i++)
    printf("%d ",heap[i]);

  getch();
}

void create(int heap[])
{
  int i,n;
  n=heap[0]; //no. of elements
  for(i=n/2;i>=1;i--)
    down_adjust(heap,i);
}

void down_adjust(int heap[],int i)
{
  int j,temp,n,flag=1;
  n=heap[0];
 
  while(2*i<=n && flag==1)
  {
    j=2*i;  //j points to left child
    if(j+1<=n && heap[j+1] > heap[j])
      j=j+1;
    if(heap[i] > heap[j])
      flag=0;
    else
    {
      temp=heap[i];
      heap[i]=heap[j];
      heap[j]=temp;
      i=j;
    }
  }
}

Output: