回文数

回文数,将数字反转在对比,是否相同

public class palindromicNumber {
    public static void main(String[] args) {
        Palindromic palindromic = new Palindromic();
        palindromic.testPalindromic(9898989);
    }
}


上面是测试:
//--------------------
下面是分装"回文"的方法:


class Palindromic {
    public void testPalindromic(Integer number) {
        Integer num = number;// 输入的数字
        System.out.println("初始输入的信息: "+num);
        if(num < 0){
            System.out.println("对不起,你输入的负数,负数不属于'回文数'");
            return;
        }
        String str = num.toString();// 转化为字符串
        int[] intArray = new int[str.length()];// 新建一个数组用来保存num每一位的数字
        for (int i = 0; i < str.length(); i++) {
            // 遍历str将每一位数字添加如intArray
            Character ch = str.charAt(i);
            //## 变成字符串,存入数组中
            intArray[i] = Integer.parseInt(ch.toString());//要点toString,不然就是传地址进去
        }
        /*检验
        for (int i = 0; i < intArray.length; i++) {
            // 遍历打印int[],察看运行结果.
            System.err.print("转化前 : " + intArray[i] + " " + "\t");
        }*/
        for (int i = 0; i <= intArray.length / 2; i++) {
            int temp = intArray[i];
            intArray[i] = intArray[intArray.length - 1 - i];
            intArray[intArray.length - 1 - i] = temp;
        }
        /*检验
        for (int i = 0; i < intArray.length; i++) {
            System.out.print("转化后 : " + intArray[i] + " ");
        }*/

        String arrayToString = Arrays.toString(intArray);
        String r = arrayToString.replace("[", " ");
        String r2 = r.replace("]", " ");
        String trim = r2.trim();
        String r3 = trim.replace(",", " ");
        String r4 = r3.replace(" ", "");
        Integer num2 = Integer.parseInt(r4);
        System.out.println("回文后的信息: "+num2);
        if (num.equals(num2)){
            System.out.println("是否是回文数: "+true);
        }else {
            System.out.println("是否是回文数: "+false);
        }
    }
}

//---------------------------------------
下面和"回文"无关:

//int类型数--组变成--Integer类型数组
class Test{
    public void a (){
        int[] nums = {1,2,3,4,5,6};
        Integer newNums[] = Arrays.stream(nums).boxed().toArray(Integer[]::new);
        System.out.println(newNums.toString());
    }
}

posted on 2022-07-19 10:38  陈嘻嘻-  阅读(55)  评论(0编辑  收藏  举报

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