ccpc热身赛题目1：中文系Roliy的困惑

代码

import java.util.ArrayList;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        ArrayList<String> list = new ArrayList<>();
        char [] charArr = new char[32];
        for (int i = 0; i < charArr.length; i++) {
            charArr[i] ='0';
        }
        Scanner sc =new Scanner(System.in);
        int x = sc.nextInt();
        while (x>0) {
            x--;
            int n =sc.nextInt();
            String binaryString = Integer.toBinaryString(n);
            char[] binaryCharArray = binaryString.toCharArray();

            for (int i = charArr.length - binaryCharArray.length, r = 0; i < charArr.length && r < binaryCharArray.length; i++, r++) {
                charArr[i] = binaryCharArray[r];
            }
            String res = String.valueOf(charArr);
           list.add(res);
        }
        for (String s : list) {
            System.out.println(s);
        }
    }
}