Check if two tree are mirror?

Question

                    50                      50
                   /  \                    /  \
                  20     30              30   20
Sample Tree<---   /  \                       /  \   ----> Mirror image
               70      80                   80   70
              /  \    \                    /    /  \  
             10  40     60                60   40   10

Answer 1

/* Given two trees, return true if they are
   mirror of each other */
int areMirror(Node* a, Node* b)
{
    /* Base case : Both empty */
    if (a==NULL && b==NULL)
        return true;

    // If only one is empty
    if (a==NULL || b == NULL)
        return false;

    /* Both non-empty, compare them recursively
     Note that in recursive calls, we pass left
     of one tree and right of other tree */
    return  a->data == b->data &&
            areMirror(a->left, b->right) &&
            areMirror(a->right, b->left);
}