题解 | #字符个数统计#
字符个数统计
https://www.nowcoder.com/practice/eb94f6a5b2ba49c6ac72d40b5ce95f50
思路清晰，一看就会。
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String s = sc.nextLine();
int n = 0;
for (int i = 0;i<s.length();i++){
if (s.indexOf(s.charAt(i)) == i){n++;
}
}
System.out.println(n);
}
}
