Heap Sort

This is the implementation of heap sort using the C programming language. If you have any doubts, please let me know.

#include<stdio.h>

int tree[50],n=0;

void del();

void ins(int);

main()

{

            int x,i,a;

            printf("\nEnter the number of elements:");

            scanf("%d",&a);

            printf("\nEnter the elements:");

            for(i=0;i<a;i++)

            {

                        scanf("%d",&x);

                        ins(x);

            }

            printf("\nAfter Sorting:\n");

            del();   

}

void ins(int x)

{

            int ptr,par;

            n=n+1;

            ptr=n;

            while(ptr>1)

            {

                        par=ptr/2;

                        if(x<=tree[par])

                        {

                                    tree[ptr]=x;

                                    return;

                        }

                        tree[ptr]=tree[par];

                        ptr=par;

            }

            tree[1]=x;

            return;

}

void del()

{

            int i,x,ptr,last,left,right;

            while(n!=0)

            {

                        x=tree[1];

                        printf(" %d  ",x);

                        last=tree[n];

                        n=n-1;

                        ptr=1;

                        left=2;

                        right=3;

                        while(right<=n)

                        {

                                    if(last>=tree[left]&&last>=tree[right])

                                    {

                                                tree[ptr]=last;

                                                break;

                                    }

                                    else if(tree[right]<=tree[left])

                                    {

                                                tree[ptr]=tree[left];

                                                ptr=left;

                                    }

                                    else

                                    {

                                                tree[ptr]=tree[right];

                                                ptr=right;

                                    }

                                    left=2*ptr;

                                    right=left+1;

                        }

                        if((left==n)&&(last<tree[left]))

                        {

                                    tree[ptr]=tree[left];

                                    ptr=left;

                        }

                        tree[ptr]=last;

}

            return;

}