思路
这一道题的关键就是去重。
思路如下:
- 将字符串变成字符数组;
- 遍历数组,将元素插入Set中;
- 统计Set的size
代码实现
import java.util.*; public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); while (scanner.hasNext()) { String str = scanner.next(); char[] chars = str.toCharArray(); Set<Character> set = new HashSet<>(); for (char aChar : chars) { set.add(aChar); } System.out.println(set.size()); } } }