void topView(Node * root) {

    vector<int> vL, vR;
    Node *t = root;

    while(t){

        t = t->left;
        if(t) vL.push_back(t->data);
    }

    t = root;

    while(t){

        vR.push_back(t->data);
        t = t->right;
    }

    for(int i=vL.size()-1; i>=0; i--) cout<<vL[i]<<" ";
    for(int i=0; i<vR.size(); i++) cout<<vR[i]<<" ";

}



    Can anyone explain why this code doesn't work?