#include <QDebug>

#include <QVector>
#include <QMap>
#include <QQueue>
#include <limits>
//-----------------------------------------------------------------------------
//Поиск родителя
QMap<int, int>::ConstIterator findParent(const QMap<int, int> &map,
                                         int child){
    QMap<int, int>::ConstIterator parent = map.find(child);

    if(child == *parent){
        return map.end();
    }

    return parent;
}
//-----------------------------------------------------------------------------
//Построение маршрута
QVector<int> route(const QMap<int, int> &map,
                   int start){
    QVector<int> route;
    route.append(start);

    forever{
        QMap<int, int>::ConstIterator parent = findParent(map, route.last());

        if(parent == map.end()){
            break;
        }

        route.append(*parent);
    };

    return route;
}
//------------------------------------------------------------------------------
//Построение маршрутов
QVector<QVector<int> > routes(const QMap<int, int> &map){
    QVector<QVector<int> > routes;
    QMap<int, int>::ConstIterator begin = map.begin();
    QMap<int, int>::ConstIterator end = map.end();

    for(; begin != end; ++begin){
        routes.append(route(map, begin.key()));
    }

    return routes;
}
//------------------------------------------------------------------------------
int main(int, char *[]){

    QMap<int, int> m;
    m[0] = 0;
    m[1] = 0;
    m[2] = 3;
    m[3] = 1;
    m[4] = 1;

    qDebug() << routes(m);

    return 0;
}