Program to connect nodes at the same level in the tree

For eg. We are given the tree in the figure(a) and we need to connect the tree node as shown in the figure (b)

#include<stdio.h>
#include<stdlib.h>
struct Tree
{
int key;
struct Tree* left;
struct Tree *right;
struct Tree *nextright;
}*root=NULL;
void displaytree(struct Tree *);
void conASL(struct Tree *);
int main()
{
struct Tree *temp;
temp= (struct Tree*)malloc(sizeof(struct Tree));
root =temp;
root->key=2;
root->nextright=NULL;
temp= (struct Tree*)malloc(sizeof(struct Tree));
temp->key=3;
temp->left=NULL;
temp->right=NULL;
temp->nextright=NULL;
root->left=temp;
temp= (struct Tree*)malloc(sizeof(struct Tree));
temp->key=4;
temp->left=NULL;
temp->right=NULL;
temp->nextright=NULL;
root->right=temp;
temp= (struct Tree*)malloc(sizeof(struct Tree));
temp->key=5;
temp->left=NULL;
temp->right=NULL;
temp->nextright=NULL;
root->left->left=temp;
temp= (struct Tree*)malloc(sizeof(struct Tree));
temp->key=6;
temp->left=NULL;
temp->right=NULL;
temp->nextright=NULL;
root->left->right=temp;
temp= (struct Tree*)malloc(sizeof(struct Tree));
temp->key=7;
temp->left=NULL;
temp->right=NULL;
temp->nextright=NULL;
root->right->left=temp;
temp= (struct Tree*)malloc(sizeof(struct Tree));
temp->key=8;
temp->left=NULL;
temp->right=NULL;
temp->nextright=NULL;
root->right->right=temp;
conASL(root);
displaytree(root);
return 0;
}
void displaytree(struct Tree *node)
{
    if(node==NULL)
        return;
printf("key=%d",node->key);
if(node->nextright==NULL)
printf("nextright=NULL");
else
printf("nextright=%d",node->nextright->key);
displaytree(node->left);
displaytree(node->right);
}
void conASL(struct Tree *node)
{
    if((node->left==NULL)&&(node->right==NULL))
        return;
    else
    {
        node->left->nextright=node->right;
        if(node->nextright==NULL)
        {
            node->right->nextright=NULL;
        }
        else
        {
        node->right->nextright=node->nextright->left;
        }
   conASL(node->left);
   conASL(node->right);
    }

}

Output: