Created
July 11, 2022 18:06
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Dijkstra's algorithm in Go
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| package main | |
| import ( | |
| "fmt" | |
| "github.com/zergon321/arrayqueue" | |
| ) | |
| type Node struct { | |
| Cost int | |
| Edges map[string]int | |
| Traversed bool | |
| Path []string | |
| } | |
| func main() { | |
| graph := map[string]*Node{ | |
| "1": &Node{ | |
| Cost: -1, | |
| Edges: map[string]int{ | |
| "2": 7, | |
| "3": 9, | |
| "6": 14, | |
| }, | |
| }, | |
| "2": &Node{ | |
| Cost: -1, | |
| Edges: map[string]int{ | |
| "3": 10, | |
| "4": 15, | |
| }, | |
| }, | |
| "3": &Node{ | |
| Cost: -1, | |
| Edges: map[string]int{ | |
| "4": 11, | |
| "6": 2, | |
| }, | |
| }, | |
| "4": &Node{ | |
| Cost: -1, | |
| Edges: map[string]int{ | |
| "2": 15, | |
| "3": 11, | |
| "5": 6, | |
| }, | |
| }, | |
| "5": &Node{ | |
| Cost: -1, | |
| Edges: map[string]int{ | |
| "4": 6, | |
| "6": 9, | |
| }, | |
| }, | |
| "6": &Node{ | |
| Cost: -1, | |
| Edges: map[string]int{ | |
| "1": 14, | |
| "3": 2, | |
| "5": 9, | |
| }, | |
| }, | |
| } | |
| queue, err := arrayqueue.NewQueue(len(graph)) | |
| handleError(err) | |
| graph["1"].Cost = 0 | |
| graph["1"].Traversed = true | |
| graph["1"].Path = []string{"1"} | |
| queue.Enqueue(graph["1"]) | |
| for queue.Length() > 0 { | |
| value, err := queue.Dequeue() | |
| handleError(err) | |
| vertex := value.(*Node) | |
| for neighbourName, edgeWeight := range vertex.Edges { | |
| cost := vertex.Cost + edgeWeight | |
| neighbour := graph[neighbourName] | |
| if neighbour.Traversed { | |
| continue | |
| } | |
| if neighbour.Cost == -1 || cost < neighbour.Cost { | |
| pathLen := len(vertex.Path) + 1 | |
| neighbour.Cost = cost | |
| neighbour.Path = make( | |
| []string, len(vertex.Path)+1) | |
| copy(neighbour.Path, vertex.Path) | |
| neighbour.Path[pathLen-1] = neighbourName | |
| } | |
| queue.Enqueue(neighbour) | |
| } | |
| vertex.Traversed = true | |
| } | |
| fmt.Println(graph) | |
| } | |
| func handleError(err error) { | |
| if err != nil { | |
| panic(err) | |
| } | |
| } |
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