binMirror.c

/*
 * ----ROHIT ROY CHOWDHURY(Zeu5)----
*/
#include <stdio.h>
#include <stdlib.h>
typedef struct S
{
	int data;
	struct S *l,*r;
} node;
void insert(node **str,int item)
{
	node *ptr = (node *)malloc(sizeof(node )),*temp;
	ptr->data=item;
	ptr->l=ptr->r=NULL;
	if(*str==NULL)
	{
		*str=ptr;
		return;
	}
	temp=*str;
	while(1)
	{
		if(item<temp->data)
		{
			if(temp->l==NULL)
			{
				temp->l=ptr;
				return;
			}
			temp=temp->l;
		}
		else
		{
			if(temp->r==NULL)
			{
				temp->r=ptr;
				return;
			}
			temp=temp->r;
		}
	}
}
void mirror(node **p,int l)//Will work with any binary tree.
{
	int i,j=0,l1,f=1;
	l1=2*l;
	node **p1=(node **)malloc(sizeof(node *)*l);//Aux. array
	node **a=(node **)malloc(sizeof(node *)*l1);//Array for storing next level
	for(i=0;i<l;i++)
		p1[i]=p[l-i-1];//to reverse the array
	for(i=0;i<l;i++)
	{
		if(p1[i]!=NULL)
		{
			a[j++]=p1[i]->r;
			a[j++]=p1[i]->l;
			if(p1[i]->l!=NULL || p1[i]->r!=NULL)//To detect intermediate levels
				f=0;
		}

	}
	j=0;
	p=p1;
	for(i=0;i<l;i++)
	{
		if(p[i]!=NULL)
		{
			p[i]->l=a[j++];
			p[i]->r=a[j++];
		}
	}

	if(f)//Stop on reaching last level
		return;
	else
		mirror(a,l1);
}
void traverse(node *p)//Level-wise traversal
{
	int f=-1,r=-1,i;
	node *q[20],*x;
	q[++r]=p;
	while(f!=r)
	{
		x=q[++f];
		if(x!=NULL)
		{
			if(x->l!=NULL)
			{
				q[++r]=x->l;
			}
			if(x->r!=NULL)
			{
				q[++r]=x->r;
			}
			printf("%d, ",x->data);
		}
	}
	puts("");
}
main()
{
	node *s,*s1;int n,f=1;
	s=NULL;
	s1=NULL;
	while(f)
	{
		puts("1.Insert.\n2.Print original tree.\n3.Exit");
		scanf("%d",&n);
		switch(n)
		{
			case 1:
				printf("Enter item - ");
				scanf("%d",&n);
				insert(&s,n);
				insert(&s1,n);
				break;
			case 2:
				traverse(s);
				break;
			case 3:
				f=0;
		}
	}
	mirror(&s1,1);
	puts("Original tree -");
	traverse(s);
	puts("Mirror -");
	traverse(s1);
}

Program to create mirror image of a binary tree.