find path

dfs.go

type Dfs struct {
	dX       []int
	dY       []int
	grid     [][]byte
	find     byte
	obstacle byte
	found    bool
}

func newDfs(grid [][]byte, find byte, obstacle byte) *Dfs {
	dX := []int{1, 1, 1, 0, 0, -1, -1, -1}
	dY := []int{1, 0, -1, 1, -1, 1, 0, -1}
	return &Dfs{dX: dX, dY: dY, grid: grid, find: find, obstacle: obstacle, found: false}
}

func (d *Dfs) possible(x, y int) {
	for i := 0; i < len(d.dX); i++ {
		_y := y + d.dY[i]
		_x := x + d.dX[i]
		if 0 <= _y && _y < len(d.grid) && 0 <= _x && _x < len(d.grid[_y]) && d.grid[_y][_x] == d.find {
			if d.reached(_x, _y) {
				return
			}
			d.grid[_y][_x] = d.obstacle
			d.possible(_x, _y)
		}
	}
}

func (d *Dfs) reached(_x, _y int) bool {
	return _y == len(d.grid)-1 && _x == len(d.grid[_y])-1
}