tp.set_floodseed(coord_def(you.x_pos, you.y_pos), true);

    coord_def       seed = you.pos();
    // "Improved" explore: keep moving in a line along the same
    // direction as the previous move, stop if we hit a barrier or
    // something that would slow us down, and use *that* as the
    // floodout seed.  This is meant to:
    //
    // 1) Prevent explore from sticking its head in a room and then
    //    backing out even though the room has unexplored corners
    //    because there are unexplored squares closer than the corners.
    //
    // 2) Similarly, prevent the bevahior of going a little bit down
    //    a long, straight corridor only to back out of it because
    //    the nearest unexplored square in that corridor is
    //    LOS_RADIUS + 1 squares away, which is further away than
    //    another unexplored square which is in the opposite direction.
    // 
    // 3) Prevent the annoying zig-zag when exploring open spaces.
    //
    // We stop at squres that would slow us down so that we won't slog
    // across a bunch of shallow water just for the sake of going in
    // a straight line.
    //
    // Not yet used with greedy explore because I can't figure out
    // how to combined it with greediness in a way that won't display
    // weird or uninuitive behavior.
    if (you.running != RMODE_EXPLORE_GREEDY && Options.explore_improved
        && (you.prev_move_x || you.prev_move_y))
    {
        coord_def prev_move_delta = you.prev_move();
        dungeon_feature_type feature;
        do {
            seed += prev_move_delta;
            feature = grd(seed);
        } while (is_travelsafe_square(seed.x, seed.y)
                 && is_traversable(feature)
                 && feature_traverse_cost(feature) == 1);
        seed -= prev_move_delta;

        // Has moving along the straight line found an unexplored
        // square?  If so, just use that square as the target.
        if (!is_terrain_seen(seed + prev_move_delta) && seed != you.pos())
        {
            you.running.x = seed.x;
            you.running.y = seed.y;
            return;
        }
    }
    tp.set_floodseed(seed, true);

    prev_move_x = 0;
    prev_move_y = 0;

    {
        you.reset_prev_move();

    }

coord_def player::prev_move() const
{
    return coord_def(prev_move_x, prev_move_y);
}
void player::reset_prev_move()
{
    prev_move_x = 0;
    prev_move_y = 0;
}

    explore_improved       = false;

    }
    else if (key == "explore_improved")
    {
        explore_improved = read_bool(field, explore_improved);

    // Going up/down stairs, going through a portal, or being banished
    // means the previous x/y movement direction is no longer valid.
    you.reset_prev_move();

  int prev_move_x;
  int prev_move_y;

    coord_def prev_move() const;
    void reset_prev_move();

    // Some experimental improvments to explore
    bool        explore_improved;

            you.reset_prev_move();

        you.prev_move_x = move_x;
        you.prev_move_y = move_y;

    {

        you.prev_move_x = move_x;
        you.prev_move_y = move_y;
    }

                explore_greedy, explore_stop, tc_reachable,

                explore_greedy, explore_stop, explore_improved, tc_reachable,

                travel_stop_message, runrest_ignore_message,                    

                travel_stop_message, runrest_ignore_message,

                trapwalk_safe_hp 

                trapwalk_safe_hp

explore_improved = false
        If set to true explore will used an expiremental improved algorithm
        which is meant to reduce backtracking and zig-zagging.  Currently
        only works with non-greedy explore.