import java.util.Arrays;

public class Javatest75 {
    /**
     *筆試題
     * 練習1：刪除字串下標是3的倍數的字元 ，s = "aabbcdeefg"，輸出abcdef
     * [a, a, b, b, c, d, e, e, f, g]
     * abcdef
     */
    public static void main(String[] args) {
        String s = "aabbcdeefg";
        //將字串轉換成字元陣列
        char[] arr = s.toCharArray();
        
 
//列印字元陣列
        System.out.println(Arrays.toString(arr));
        //遍歷字元陣列，將下標是3的倍數的字元替換成‘ ’
        for (int i = 0; i < arr.length; i++) {
            if(i % 3 == 0){
                arr[i] = ' ';
            }
        }
        StringBuilder s1 = new StringBuilder();
        //遍歷字元陣列，將不是空格的字元按順序一次新增至s1
 

        for (int j = 0; j < arr.length; j++) {
            if(arr[j] == ' '){
                continue;
            }
            s1.append(arr[j]);
        }
        //列印s1
        System.out.println(s1.toString());

    }
}