interface{} Pointers

In line ABCD, which ones of them have syntax issues?

package main
type S struct {
}
func f(x interface{}) {
}
func g(x *interface{}) {
}
func main() {
    s := S{}
    p := &s
    f(s) //A
    g(s) //B
    f(p) //C
    g(p) //D
}

Answer

package main
type S struct {
}
func f(x interface{}) {
}
func g(x *interface{}) {
}
func main() {
    s := S{}
    p := &s
    f(s) //A correct
    g(s) //B incorrect
    f(p) //C correct
    g(p) //D incorrect
}
                            

Temporary Pointer

Explain why the printed output of below are 333, and modify line A to assure 012 is printed.

package main
const N = 3
func main() {
    m := make(map[int]*int)
    for i := 0; i < N; i++ {
        m[i] = &i //A
    }
    for _, v := range m {
        print(*v)
    }
}

Answer

package main
const N = 3
func main() {
    m := make(map[int]*int)
    for i := 0; i < N; i++ {
        j := int(i)
        m[i] = &j
    }
    for _, v := range m {
        print(*v)
    }
}