一個5位數，判斷它是不是迴文數。即12321是迴文數，個位與萬位相同，十位與千位相同

publicclass lesson1_31 {

       publicstaticvoid paduan(String num) {

              int j = 0, i = 0, count = 0;

              for (i = 0, j = num.length() - 1; i < num.length() / 2; i++, j--)

                     if (num.charAt(i) == num.charAt(j)) {

                            count++;

                     }

              if (count == num.length() / 2) {

                     System.out.println(num + "是迴文數！");

              } else

                     System.out.println(num + "不是迴文數！");

       }

       publicstaticvoid main(String[] args) {

              paduan("12321");

              paduan("123321");

              paduan("123467321");

       }

}

 

運行結果：

12321是迴文數！

123321是迴文數！

123467321不是迴文數！