CareerCup

If we are talking about a binary tree shape similarity, then the below code does it (descriptions inlined):

bool issame(node* root, node* root1)
{
    // special case when the two nodes are NULL at the same time
    if (root == root1)
        return true;
    
    // if we have differing shapes at this level    
    if ((NULL == root && NULL != root1)  
        || (NULL == root1 && NULL != root) )
        return false;
    
    // recurse into subtrees
    return (root->data == root1->data && issame(root->left, root1->left) &&  issame(root->right, root1->right));
}

What does this even mean?!

what kind of tree?
similar to what?
what does "structurally similar" mean?

I think the question should be asking to check if two (binary) trees are structurally similar, in which case you can use recursion to solve the problem.

Equal number of left and right nodes ?

1. do tree traversal
2. if any of them hits the NULL after the leaf node then chek for another one doing the same or not.

int  flag = 0;

bool  chekSimilatTree( tree1 root1, tree2 root2) {

if( (root1==NULL && root2!=NULL) || (root2==NULL && root1!=NULL) ) {

flag=1; return ;

}

if (root1==NULL && root2==NULL )

return ;

chekSimilarTree ( root1->left, root2->left);

chekSimilarTree( root1->right, root2->right );

if( flag==1 )

return false;

else  return true;

}

flag should be global

If structurally similar means : in binary tree the alignment of tree is same but values can be different then...

int strSimilar(struct node *root1,struct node *root2)
{
    if(root1==NULL && root2==NULL)
        return 1;
    if(root1==NULL || root2== NULL)
        return 0;
    return strSimilar(root1->left,root2->left) && strSimilar(root1->right,root2->right);

}