paizaの練習問題を解く 1マスの陣取り2 Go編

package main
import "fmt"
func main(){
    var h, w int
    fmt.Scan(&h, &w)
    
    s := make([]string, h)
    var sy, sx int
    for i := 0; i < h; i++ {
        fmt.Scan(&s[i])
        for j, v := range s[i] {
            if v == '*' {
                sy = i
                sx = j
            }
        }
    }
    
    for i := 0; i < 4; i++ {
        var ly, lx int
        switch i {
            case 0: ly, lx = sy + 1, sx
            case 1: ly, lx = sy - 1, sx
            case 2: ly, lx = sy, sx + 1
            case 3: ly, lx = sy, sx - 1
        }
        
        if ly >= 0 && lx >= 0 && ly < h && lx < w && s[ly][lx] != '#' {
            runes := []rune(s[ly])
            runes[lx] = '*'
            s[ly] = string(runes)
        }
    }
    
    for i := 0; i < h; i++ {
        fmt.Println(s[i])
    }
}