Changing it into a graph
Since that's what they actually want, even though the exercise says it's a tree
This commit is contained in:
parent
dc34a45b94
commit
42d8211402
BIN
go/pov/cmd/cmd
BIN
go/pov/cmd/cmd
Binary file not shown.
@ -8,19 +8,13 @@ import (
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func main() {
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g := pov.New()
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g.AddNode("parent")
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g.AddArc("parent", "x")
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g.AddArc("x", "sib-2")
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g.AddArc("x", "sib-3")
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g.AddArc("x", "sib-4")
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g.AddNode("sibling")
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g.AddNode("x")
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g.AddArc("parent", "sibling")
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g.AddArc("sibling", "child-1")
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g.AddArc("sibling", "child-2")
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g.AddArc("sibling", "child-3")
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g.AddArc("child-3", "grandchild-1")
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g.AddArc("grandchild-1", "greatgrandchild-1")
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pov.PrintGraph(g)
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g.AddArc("parent", "x")
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fmt.Println("== Change Root to child-3 ==")
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n := g.ChangeRoot("parent", "child-3")
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pov.PrintGraph(n)
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g.Print("parent")
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n := g.ChangeRoot("parent", "x")
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fmt.Println(n.ArcList())
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g.Print("x")
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}
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192
go/pov/pov.go
192
go/pov/pov.go
@ -2,8 +2,14 @@ package pov
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const testVersion = 2
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// A Graph is just a collection of Nodes
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type Node struct {
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label string
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connections []Node
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}
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type Graph struct {
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leaves []Node
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nodes []Node
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}
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func New() *Graph {
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@ -11,124 +17,120 @@ func New() *Graph {
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}
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func (g *Graph) AddNode(lbl string) {
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// Make sure that g doesn't already have node lbl
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if g.getNode(lbl) != nil {
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return
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if g.getNode(lbl) == nil {
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g.nodes = append(g.nodes, Node{label: lbl})
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}
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g.leaves = append(g.leaves, Node{label: lbl})
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}
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func (g *Graph) AddArc(fr, to string) {
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if frN := g.getNode(fr); frN != nil {
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frN.AddNode(to)
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}
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}
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func (g *Graph) ArcList() []string {
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var arcList []string
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for i := range g.leaves {
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arcList = append(arcList, g.leaves[i].ArcList()...)
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}
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return arcList
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}
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func (g *Graph) GetPath(fr, to string) []string {
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if frN := g.getNode(fr); frN != nil {
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return frN.GetPath(to)
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}
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return []string{}
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}
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func (g *Graph) getNode(lbl string) *Node {
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for i := range g.leaves {
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if r := g.leaves[i].getNode(lbl); r != nil {
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return r
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for i := range g.nodes {
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if g.nodes[i].label == lbl {
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return &g.nodes[i]
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}
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}
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return nil
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}
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// Return a graph from 'newRoot's POV
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func (g *Graph) ChangeRoot(oldRoot, newRoot string) *Graph {
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root := g.getNode(newRoot)
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if root == nil {
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return nil
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func (g *Graph) AddArc(fr, to string) {
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frN := g.getNode(fr)
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if frN == nil {
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g.AddNode(fr)
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frN = g.getNode(fr)
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}
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ret := New()
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//pth := g.GetPath(oldRoot, newRoot)
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if root.parent != nil {
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root.parent.removeLeaf(root.label)
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root.parent.parent = root
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root.addWholeNode(root.parent)
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root.parent = nil
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toN := g.getNode(to)
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if g.getNode(to) == nil {
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g.AddNode(to)
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toN = g.getNode(to)
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}
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ret.addWholeNode(root)
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return ret
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frN.connections = append(frN.connections, *toN)
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}
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func (g *Graph) addWholeNode(n *Node) {
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g.leaves = append(g.leaves, *n)
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}
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type Node struct {
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label string
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leaves []Node
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parent *Node
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}
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func (n *Node) AddNode(lbl string) {
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nn := Node{label: lbl, parent: n}
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n.leaves = append(n.leaves, nn)
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}
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func (n *Node) addWholeNode(nd *Node) {
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n.leaves = append(n.leaves, *nd)
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}
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func (n *Node) removeLeaf(lbl string) {
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for i := range n.leaves {
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if n.leaves[i].label == lbl {
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n.leaves = append(n.leaves[:i], n.leaves[i+1:]...)
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}
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}
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}
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func (n *Node) ArcList() []string {
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func (g *Graph) ArcList() []string {
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var ret []string
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for i := range n.leaves {
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// Append this arc
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ret = append(ret, n.label+" -> "+n.leaves[i].label)
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// Append all sub-arcs
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ret = append(ret, n.leaves[i].ArcList()...)
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for _, k := range g.nodes {
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for _, l := range k.connections {
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ret = append(ret, k.label+" -> "+l.label)
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}
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}
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return ret
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}
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// GetPath returns a string slice of all leaves leading to 'to'
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func (n *Node) GetPath(to string) []string {
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ret := []string{n.label}
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if n.label == to {
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return ret
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// getPath returns the shortest path from 'fr' to 'to'
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func (g *Graph) getPath(fr, to string) []string {
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if fr == to {
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return []string{fr}
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}
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for i := range n.leaves {
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if toN := n.leaves[i].getNode(to); toN != nil {
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// This is the leaf to follow
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return append(ret, n.leaves[i].GetPath(to)...)
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st := g.getNode(fr)
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if st == nil {
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// Couldn't find the starting node
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return []string{}
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}
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var valPaths [][]string
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for i := range st.connections {
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if st.connections[i].label == to {
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return []string{fr, to}
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}
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tst := g.getPath(st.connections[i].label, to)
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if len(tst) > 0 {
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valPaths = append(valPaths, tst)
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}
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}
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// Couldn't get there
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return []string{}
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if len(valPaths) == 0 {
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// No valid paths found
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return []string{}
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}
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var ret []string
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for i := range valPaths {
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if len(valPaths[i]) < len(ret) || len(ret) == 0 {
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ret = valPaths[i]
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}
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}
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return ret
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}
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// Returns the node with label lbl or nil
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func (n *Node) getNode(lbl string) *Node {
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if n.label == lbl {
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return n
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func (g *Graph) ChangeRoot(oldRoot, newRoot string) *Graph {
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pth := g.getPath(oldRoot, newRoot)
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if len(pth) == 0 {
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// No valid path
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return g
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}
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for i := range n.leaves {
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if r := n.leaves[i].getNode(lbl); r != nil {
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return r
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for oldRoot != newRoot {
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// We just keep swapping the first two in pth until we're done
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if len(pth) >= 2 {
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n := g.getNode(pth[1])
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if n == nil {
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return g
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}
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n = n.copy()
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p := g.getNode(pth[0])
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if p == nil {
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return g
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}
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p = p.copy()
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p.removeConnection(n.label)
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n.connections = append(n.connections, *p)
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oldRoot = n.label
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}
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}
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return nil
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return g
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}
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func (n *Node) removeConnection(to string) {
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for i, k := range n.connections {
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if k.label == to {
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copy(n.connections[i:], n.connections[i+1:])
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n.connections[len(n.connections)-1] = Node{}
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n.connections = n.connections[:len(n.connections)-1]
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}
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}
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}
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// Node.copy() returns a new node that is a copy of this node
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func (n *Node) copy() *Node {
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ret := Node{label: n.label}
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for _, k := range n.connections {
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cp := k.copy()
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ret.connections = append(ret.connections, *cp)
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}
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return &ret
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}
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@ -5,20 +5,19 @@ import (
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"strings"
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)
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func PrintGraph(g *Graph) {
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for i := range g.leaves {
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PrintNode(&g.leaves[i], 1)
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func (g *Graph) Print(root string) {
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r := g.getNode(root)
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if r != nil {
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r.Print(0)
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} else {
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fmt.Println("Couldn't find root node:", root)
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}
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}
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func PrintNode(n *Node, lvl int) {
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fmt.Print(strings.Repeat(" ", lvl))
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if n.parent == nil {
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fmt.Println("{label:", n.label, "}")
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} else {
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fmt.Println("{label:", n.label, ", parent:", n.parent.label, "}")
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}
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for i := range n.leaves {
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PrintNode(&n.leaves[i], lvl+1)
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func (n *Node) Print(ind int) {
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pad := strings.Repeat(" ", ind)
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fmt.Println(pad + n.label)
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for i := range n.connections {
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n.connections[i].Print(ind + 1)
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}
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}
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@ -1,6 +1,7 @@
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package pov
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import (
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"fmt"
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"reflect"
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"sort"
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"testing"
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@ -266,10 +267,13 @@ func TestTestVersion(t *testing.T) {
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}
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func TestConstruction(t *testing.T) {
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fmt.Println("TestConstruction")
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for _, tc := range testCases {
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fmt.Println("Starting test:", tc.description)
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got := tc.graph().ArcList()
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want := tc.arcStrings
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tc.testResult(got, want, "incorrect graph construction", t)
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fmt.Println(" Test Passed:", tc.description)
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}
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}
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206
go/pov/tree/pov.go
Normal file
206
go/pov/tree/pov.go
Normal file
@ -0,0 +1,206 @@
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package pov
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const testVersion = 2
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type Graph struct {
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leaves []Node
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Iters int
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}
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func New() *Graph {
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return new(Graph)
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}
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func (g *Graph) AddNode(lbl string) {
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// Make sure that g doesn't already have node lbl
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if g.getNode(lbl) != nil {
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return
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}
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g.leaves = append(g.leaves, Node{label: lbl})
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}
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func (g *Graph) AddArc(fr, to string) {
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var frN *Node
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if frN = g.getNode(fr); frN == nil {
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// frN doesn't exist yet... Create it and
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// drop
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frN = &Node{label: fr}
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}
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frN.AddNode(to)
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}
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func (g *Graph) ArcList() []string {
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var arcList []string
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for i := range g.leaves {
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arcList = append(arcList, g.leaves[i].ArcList()...)
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}
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return arcList
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}
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func (g *Graph) GetPath(fr, to string) []string {
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if frN := g.getNode(fr); frN != nil {
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return frN.GetPath(to)
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}
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return []string{}
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}
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func (g *Graph) getNode(lbl string) *Node {
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for i := range g.leaves {
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if r := g.leaves[i].getNode(lbl); r != nil {
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return r
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}
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}
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return nil
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}
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// Return a graph from newRoot's POV
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func (g *Graph) ChangeRoot(oldRoot, newRoot string) *Graph {
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ret := g
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pth := ret.GetPath(oldRoot, newRoot)
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for oldRoot != newRoot {
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// Swap the first two in pth
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if len(pth) >= 2 {
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n := ret.getNode(pth[1])
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if n == nil {
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return ret
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}
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n = n.copy()
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p := ret.getNode(pth[0])
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if p == nil {
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return ret
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}
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p = p.copy()
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if n != nil && p != nil {
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p.removeLeaf(n.label)
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n.addWholeNode(p)
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if p.parent != nil {
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n.parent = p.parent
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p.parent = nil
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} else {
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n.parent = nil
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}
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}
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ret = New()
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ret.addWholeNode(n)
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oldRoot = n.label
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}
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pth = ret.GetPath(oldRoot, newRoot)
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}
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return ret
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}
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/*
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// Return a graph from newRoot's POV
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func (g *Graph) ChangeRoot(oldRoot, newRoot string) *Graph {
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if oldRoot == newRoot {
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return g
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}
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ret := New()
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pth := g.GetPath(oldRoot, newRoot)
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fmt.Println(pth)
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// Swap the first two in pth
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if len(pth) >= 2 {
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fmt.Println("Swap ", pth[0], "<>", pth[1])
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n := g.getNode(pth[1])
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p := g.getNode(pth[0])
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if n != nil && p != nil {
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p.removeLeaf(n.label)
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n.addWholeNode(p)
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if p.parent != nil {
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n.parent = p.parent
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p.parent = nil
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} else {
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n.parent = nil
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}
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}
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ret.addWholeNode(n)
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}
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PrintGraph(ret)
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if pth[1] != newRoot {
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fmt.Println("Recurse:", pth[1], "<>", newRoot)
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return ret
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//return ret.ChangeRoot(pth[1], newRoot)
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} else {
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return ret
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}
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}
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*/
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func (g *Graph) addWholeNode(n *Node) {
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g.leaves = append(g.leaves, *n)
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}
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|
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type Node struct {
|
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label string
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leaves []Node
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parent *Node
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}
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|
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func (n *Node) copy() *Node {
|
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// Returns a new node that is a copy of this node
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ret := Node{label: n.label, parent: n.parent}
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for _, k := range n.leaves {
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cp := k.copy()
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ret.leaves = append(ret.leaves, *cp)
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}
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return &ret
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}
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func (n *Node) AddNode(lbl string) {
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nn := Node{label: lbl, parent: n}
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n.leaves = append(n.leaves, nn)
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}
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func (n *Node) addWholeNode(nd *Node) {
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n.leaves = append(n.leaves, *nd)
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}
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func (n *Node) removeLeaf(lbl string) {
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for i, k := range n.leaves {
|
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if k.label == lbl {
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copy(n.leaves[i:], n.leaves[i+1:])
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n.leaves[len(n.leaves)-1] = Node{}
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n.leaves = n.leaves[:len(n.leaves)-1]
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}
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}
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}
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|
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func (n *Node) ArcList() []string {
|
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var ret []string
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for i := range n.leaves {
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// Append this arc
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ret = append(ret, n.label+" -> "+n.leaves[i].label)
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// Append all sub-arcs
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ret = append(ret, n.leaves[i].ArcList()...)
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}
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return ret
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}
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|
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// GetPath returns a string slice of all leaves leading to 'to'
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func (n *Node) GetPath(to string) []string {
|
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ret := []string{n.label}
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if n.label == to {
|
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return ret
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}
|
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for i := range n.leaves {
|
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if toN := n.leaves[i].getNode(to); toN != nil {
|
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// This is the leaf to follow
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return append(ret, n.leaves[i].GetPath(to)...)
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}
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}
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// Couldn't get there
|
||||
return []string{}
|
||||
}
|
||||
|
||||
// Returns the node with label lbl or nil
|
||||
func (n *Node) getNode(lbl string) *Node {
|
||||
if n.label == lbl {
|
||||
return n
|
||||
}
|
||||
for i := range n.leaves {
|
||||
if r := n.leaves[i].getNode(lbl); r != nil {
|
||||
return r
|
||||
}
|
||||
}
|
||||
return nil
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user