First of all, let’s introduce what is a palindrome number?
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is the number 12321, 11111, 63936. If you read it forward and backward, it is the same number. It is called Palindrome number.
Two operations: / and %
/: division operation. It should be noted here that if two integers get along with each other, the result will also be an integer. For example, 3/2=1. 2/3=0.
%: Touch: Remainder operation. For example, 1%3=1. 13 =3.
The idea of judging palindrome numbers:
One way of thinking is this: just invert the number (123 becomes 321) and then determine whether the two are equal.
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Implementation code:
public class Test{ public static void main(String[]args){ System.out.println("请输入一个数字"); Scanner reader = new Scanner(System.in); int num = reader.nextInt(); Judge (num); } private static void Judge(int num){ int num2=0;//这个数用来存储倒置后的数字 int num3=num;//因为以后会用到 num num的数会改变所以再用一个变量记录一下num //下面我们开始我们的循环 while(num>0){ num2 = num2*10+num%10; num = num/10; } if (num2 == num3) {//若倒置后的数字与原先的数字相等则说明为回文数 System.out.println("该数是回文数"); } else { System.out.println("该不是回文数"); } } }
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