Example #1
0
func tarjanSort(successors map[bson.ObjectId][]bson.ObjectId) [][]bson.ObjectId {
	// http://en.wikipedia.org/wiki/Tarjan%27s_strongly_connected_components_algorithm
	data := &tarjanData{
		successors: successors,
		nodes:      make([]tarjanNode, 0, len(successors)),
		index:      make(map[bson.ObjectId]int, len(successors)),
	}

	for id := range successors {
		id := bson.ObjectId(string(id))
		if _, seen := data.index[id]; !seen {
			data.strongConnect(id)
		}
	}

	// Sort connected components to stabilize the algorithm.
	for _, ids := range data.output {
		if len(ids) > 1 {
			sort.Sort(idList(ids))
		}
	}
	return data.output
}
Example #2
0
func bid(n int) bson.ObjectId {
	return bson.ObjectId(fmt.Sprintf("%024d", n))
}