Tower of Hanoi

void tower(int N, int m, int n, vector<pair<int, int>>& v){
    if(N == 1){
        v.push_back({m, n});
    } else{
        if(m == 1 && n == 2){
            tower(N-1, 1, 3, v);
            v.push_back({m, n});
            tower(N-1, 3 ,2, v);
        } else if(m == 3 && n == 2){
            tower(N-1, 3, 1, v);
            v.push_back({m, n});
            tower(N-1, 1, 2, v);
        } else if(m == 3 && n == 1){
            tower(N-1, 3, 2, v);
            v.push_back({m, n});
            tower(N-1, 2, 1, v);
        } else if(m == 2 && n == 1){
            tower(N-1, 2, 3, v);
            v.push_back({m, n});
            tower(N-1, 3, 1, v);
        } else if(m == 2 && n == 3){
            tower(N-1, 2, 1, v);
            v.push_back({m, n});
            tower(N-1, 1, 3, v);
        } else{
            tower(N-1, 1, 2, v);
            v.push_back({m, n});
            tower(N-1, 2, 3, v);
        }
    }
}

vector<int> shiftPile(int N, int n){
    vector<pair<int,int>> v;
    vector<int> p;
    tower(N, 1, 3, v);
    p.push_back(v[n-1].first);
    p.push_back(v[n-1].second);
    return p;
}