题解 | 简写单词

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        String n = in.nextLine();
        String[] arr = n.split(" ");
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < arr.length; i++) {
            char c = arr[i].charAt(0);
            if (!n.isEmpty()) {//避免空元素
                sb.append(Character.toUpperCase(c));
            }
        }
        System.out.println(sb);
    }
}