func (g *Graph) Traverse(privateState PrivateTraverseState, from, to *Node) (path []*Node, totalCost float64, ok bool) {
seen := make(map[*Node]bool)
state := &PublicTraverseState{0.0, from, &VisitedList{from, nil}, privateState}
sh := sheap.NewSliceHeap(PublicStateLessThan)
heap.Init(sh)
heap.Push(sh, state)
for !sh.IsEmpty() {
state = heap.Pop(sh).(*PublicTraverseState)
if _, found := seen[state.node]; found {
continue
}
seen[state.node] = true
if DEBUG&PROGRESSIVE_FLAG != 0 {
fmt.Printf("%f : %s\n", state.totalCost, state.node.Record)
}
if state.node == to {
return state.visited.MakeSlice(), state.totalCost, true
}
for _, vertex := range state.node.vertices {
if DEBUG&TRAVERSE_FLAG != 0 {
fmt.Printf("Considering %s to %s ... ", state.node.Record, vertex.To.Record)
}
totalCost := state.totalCost + vertex.Cost
nextNode := vertex.To
if state.visited.HasVisited(nextNode) {
if DEBUG&TRAVERSE_FLAG != 0 {
fmt.Println("already been there")
}
continue
}
nextPrivateState, ok := (state.privateState).TraverseStateHelper(vertex)
if !ok {
if DEBUG&TRAVERSE_FLAG != 0 {
fmt.Println("rejected by calling code")
}
continue
}
nextPublicState := &PublicTraverseState{totalCost, nextNode, &VisitedList{nextNode, state.visited}, nextPrivateState}
heap.Push(sh, nextPublicState)
if DEBUG&TRAVERSE_FLAG != 0 {
fmt.Printf("good w/ total cost of %f\n", totalCost)
}
}
}
return nil, 0.0, false
}
func NewPriorityQueue(f func(a, b interface{}) bool) *PriorityQueue {
sh := sheap.NewSliceHeap(f)
heap.Init(sh)
return &PriorityQueue{sh}
}