chessKnight.go

func solution(cell string) int {
    p, c := NewPos(cell), 0
    for _, v := range p.Moves() {
        if p.Move(v).isOn() { c++ }
    }
    return c
}

type pos struct {
    x, y int
}

func NewPos(cell string) pos {
    return pos{int(cell[0]-'a'),int(cell[1]-'1')}
}


func (p pos) isOn() bool {
    return p.x >=0 && p.x <=7 && p.y >=0 && p.y <=7
}

func (p pos) Move(xy []int) pos {
    r := p
    r.x += xy[0]
    r.y += xy[1]
    return r
}

func (p *pos) Moves() [][]int {
    return [][]int{
        {-2, 1}, {-1, 2},   {1, 2}, {2, 1}, 
        {-2, -1}, {-1, -2}, {1, -2}, {2, -1}, 
    }
}