题解 | 字符串分隔

先使用padding将输入字符串input用'0'补齐到8的倍数，然后检查index是否为8的倍数换行即可。

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;

public class Main {
    public static void main(String[] args) {
        try (BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
                    PrintWriter out = new PrintWriter(System.out)) {
            String input = in.readLine();
            // 计算需要补零的数量
            int padding = 8 - (input.length() % 8);
            if (padding != 8) {
                StringBuilder sb = new StringBuilder(input);
                for (int i = 0; i < padding; i++) {
                    sb.append('0');
                }
                input = sb.toString();
            }
            // 按每8个字符一组输出
            for (int i = 0; i < input.length(); i++) {
                out.print(input.charAt(i));
                if ((i + 1) % 8 == 0) {
                    out.println();
                }
            }
            out.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}