private void setPointPair(double d, int left, int right) {
        if (d > minDis) {
            return;
        } else if (d < minDis) {
            minDis = d;
            ArrayList<PointPair> ppList = new ArrayList<PointPair>();
            ppList.add(new PointPair(points[left], points[right]));
            resultMap.put(minDis, ppList);
        } else {
            ArrayList<PointPair> ppList = resultMap.get(minDis);
            ppList.add(new PointPair(points[left], points[right]));
        }
    }