void shortestpath( const std::vector >& paths, int from, std::vector< short>& path){
    std:: vector flags(paths.size(), false);
    std:: vector distance(paths.size(), 0);
    path.resize(paths.size(), 0);

    for(size_t i = 0; i != paths.size(); ++i){
        distance[i] = paths[from][i];
    }

    flags[from] = 1;

    int min, pos;
    for(size_t i = 1; i != paths.size(); ++i){
        pos = -1;
        min = std:: numeric_limits::max();
        for(size_t j = 0; j != paths.size(); ++j){
            if(!flags[j] && distance[j] < min){
                min = distance[j];
                pos = j;
            }
        }

        if(pos == -1)
            break;

        flags[pos] = true;

        for(size_t j = 0; j != paths.size(); ++j){
            if(!flags[j] && paths[pos][j] != 0
                && paths[pos][j] < std::numeric_limits :: max()
                && min+paths[pos][j] < distance[j]){
                distance[j] = min + paths[pos][j];
                path[j] = pos;
            }
        }
    }

    for(size_t i = 0; i != distance.size(); ++i){
        std::cout > vj >> weight;
        paths[vi][vj] = weight;
        paths[vj][vi] = weight;
    }

    std:: vector path;
    shortestpath(paths, 0, path);

    std::cout