func ShortestPath(g *graph.DirGraph, start graph.VertexId) (dist map[graph.VertexId]int) {
dist = make(map[graph.VertexId]int)
visited := make(map[graph.VertexId]bool)
getDist := func(v graph.VertexId) {
neighbours := g.GetNeighbours(v).VerticesIter()
visited[v] = true
for neighbour := range neighbours {
ok, _ := visited[neighbour]
if !ok {
dist[neighbour] = dist[v] + 1
}
}
}
bfs.Bfs(g, start, getDist)
return
}
func Bfs(g *graph.DirGraph, start graph.VertexId, fn func(graph.VertexId)) {
queue := []graph.VertexId{start}
visited := make(map[graph.VertexId]bool)
var next []graph.VertexId
for len(queue) > 0 {
next = []graph.VertexId{}
for _, vertex := range queue {
visited[vertex] = true
neighbours := g.GetNeighbours(vertex).VerticesIter()
fn(vertex)
for neighbour := range neighbours {
_, ok := visited[neighbour]
if !ok {
next = append(next, neighbour)
}
}
}
queue = next
}
}
