func Search(start gocube.CubieCube, heuristic EdgesHeuristic,
d int) []gocube.Move {
if d == 0 {
if IsSolved(start) {
return []gocube.Move{}
} else {
return nil
}
} else if heuristic.Lookup(start) > d {
return nil
}
for m := 0; m < 18; m++ {
newCube := start
newCube.Move(gocube.Move(m))
if solution := Search(newCube, heuristic, d-1); solution != nil {
return append([]gocube.Move{gocube.Move(m)}, solution...)
}
}
return nil
}
func solve2x2x3(start gocube.CubieCube, depth, lastFace int) []gocube.Move {
if depth == 0 {
if solved, _ := Is2x2x3Solved(start); solved {
return []gocube.Move{}
} else {
return nil
}
}
for m := 0; m < 18; m++ {
move := gocube.Move(m)
face := move.Face()
if face == lastFace {
continue
}
newCube := start
newCube.Move(move)
if solution := solve2x2x3(newCube, depth-1, face); solution != nil {
return append([]gocube.Move{move}, solution...)
}
}
return nil
}
func solve2x2x2Search(start gocube.CubieCube, depth, lastFace int,
previousMoves []gocube.Move, output chan<- []gocube.Move) {
if depth == 0 {
if solved, _ := Is2x2x2Solved(start); solved {
newArray := make([]gocube.Move, len(previousMoves))
copy(newArray, previousMoves)
output <- newArray
}
return
}
for m := 0; m < 18; m++ {
move := gocube.Move(m)
face := move.Face()
if face == lastFace {
continue
}
newCube := start
newCube.Move(move)
previousMoves := append(previousMoves, move)
solve2x2x2Search(newCube, depth-1, face, previousMoves, output)
previousMoves = previousMoves[:len(previousMoves)-1]
}
}
func NewEdgesHeuristic(maxDepth int) EdgesHeuristic {
res := EdgesHeuristic{map[string]int{}, maxDepth}
queue := []EdgesHeuristicNode{EdgesHeuristicNode{gocube.SolvedCubieEdges(),
HashEdges(gocube.SolvedCubieEdges()), 0}}
for len(queue) > 0 {
node := queue[0]
queue = queue[1:]
if _, ok := res.Mapping[node.Hash]; ok {
continue
}
res.Mapping[node.Hash] = node.Depth
if node.Depth == maxDepth {
continue
}
for move := 0; move < 18; move++ {
newEdges := node.Edges
newEdges.Move(gocube.Move(move))
hash := HashEdges(newEdges)
queue = append(queue, EdgesHeuristicNode{newEdges, hash,
node.Depth + 1})
}
}
return res
}
func solveAllButL5C(start gocube.CubieCube, depth, lastFace int) []gocube.Move {
if depth == 0 {
if solved := IsAllButL5CSolved(start); solved {
return []gocube.Move{}
} else {
return nil
}
} else if globalEdgesHeuristic.Lookup(start.Edges) > depth {
return nil
}
for m := 0; m < 18; m++ {
move := gocube.Move(m)
face := move.Face()
if face == lastFace {
continue
}
newCube := start
newCube.Move(move)
if solution := solveAllButL5C(newCube, depth-1, face); solution != nil {
return append([]gocube.Move{move}, solution...)
}
}
return nil
}