771. 宝石与石头

771. 宝石与石头

package main
import "fmt"
func numJewelsInStones(J string, S string) int {
     m :=make(map[byte]struct{})
    for i :=range J{
         m[J[i]]= struct{}{}
    }
    var res int
    for i :=range S{
        if  _,ok:=m[S[i]];ok{
            res++
        }
    }
    return res
}
func main() {
    fmt.Println(numJewelsInStones("aA","aAAbbbb"))
    fmt.Println(numJewelsInStones("z","ZZ"))
}