sober-bishop/main.go

package main

import "fmt"

var (
	// 4x4 board with node counts
	StartingBoard = map[int]int{
		10: 2, 11: 3, 12: 3, 13: 3,
		20: 1, 21: 4, 22: 5, 23: 9,
		30: 0, 31: 2, 32: 2, 33: 4,
		40: 0, 41: 1, 42: 3, 43: 0,
	}
)

func FindMove(s int, b map[int]int, p string) (ok bool, paths []string) {
	// Found possible path
	if s == 20 {
		return true, append(paths, p)
	}
	// deincrement the starting point
	b[s] -= 1

	// what are M valid directions
	NW := s - 11
	NE := s - 9
	SW := s + 9
	SE := s + 11

	if b[NW] != 0 { // NW
		ok, r := FindMove(NW, b, (p + "NW"))
		if ok {
			paths = append(paths, r...)
		}
	}
	if b[NE] != 0 { // NE
		ok, r := FindMove(NE, b, (p + "NE"))
		if ok {
			paths = append(paths, r...)
		}
	}
	if b[SW] != 0 { // SW
		ok, r := FindMove(SW, b, (p + "SW"))
		if ok {
			paths = append(paths, r...)
		}
	}
	if b[SE] != 0 { // SE
		ok, r := FindMove(SE, b, (p + "SE"))
		if ok {
			paths = append(paths, r...)
		}
	}

	return true, paths
}

func main() {
	// queue := make(chan int, 4)

	// walk and find nodes
	// := FindPath()

	board := StartingBoard
	board[22] -= 1
	_, moves := FindMove(22, board, "")

	// Get valid nodes
	for _, n := range moves {
		fmt.Println(n)
	}
}