Try simple approach:

Node *lca(Node root, int v1,int v2) { // Write your code here. Node roottemp = root; Node* arrV1[50] = {0}; Node* arrV2[50] = {0}; int index1 = 0; int index2= 0; int min =0;

    if(root == NULL)
    {
        return NULL;
    }

    while(root!= NULL)
    {
        if(root->data == v1)
        {

            arrV1[index1] = root;
            index1++;
            break;
        }
        arrV1[index1] = root; 
        root->data > v1? (root = root->left) : (root = root->right);
        index1++;
    }

    root = roottemp;

    while(root!= NULL)
    {
        if(root->data == v2)
        {
            arrV2[index2] = root;
            index2++;
            break;
        }
        arrV2[index2] = root; 
        root->data > v2? (root = root->left) : (root = root->right);
        index2++;
    }

    index1>index2? min = index2: min = index1;

    for (int i=0 ; i<min; )
    {
           if(arrV1[i] == arrV2[i])
           {
               roottemp = arrV1[i];
               i++;
           }
           else{
               break;
           }
    }return roottemp;
}

}; //End of Solution