JAVA 使用算术运算符得到一个4位数十进制的各位数字并输出，然后输出该数的逆序数和个位数字平方后相加的

Answer 1

import java.util.Scanner;

public class Main {

public static void dealNumber(int num){
if(num<0||num>9999) throw new IllegalArgumentException();
int g,s,b,q;
g=num%10;
num/=10;
s=num%10;
num/=10;
b=num%10;
num/=10;
q=num;
System.out.println("个位="+g);
System.out.println("十位="+s);
System.out.println("百位="+b);
System.out.println("千位="+q);
System.out.println();
System.out.println("倒序="+g+s+b+q);
System.out.println();
System.out.println("各位平方和="+(g*g+s*s+b*b+q*q));
}

public static void main(String[] args) {
Scanner scan=new Scanner(System.in);
System.out.print("请输入数字(0-9999):");
int num=scan.nextInt();
dealNumber(num);
}

}

Answer 2

import java.util.*;
public class A
{
public static void main(String[] args)
{
int num=0;
Scanner s=new Scanner(System.in);
System.out.println("请输入一个四位正整数:");
int a=s.nextInt();
String str=String.valueOf(a);
int[] b=new int[str.length()];
System.out.println("各位数字分别为:");
for(int i=0;i<b.length;i++)
{
b[i]=Integer.parseInt(str.charAt(i)+"");
System.out.print(b[i]+",");
}
System.out.println();
System.out.println("倒序为:");
for(int i=b.length-1;i>=0;i--)
{
System.out.print(b[i]);
}
System.out.println("各位数平方之和:");
for(int i=0;i<b.length;i++)
{
num+=b[i]*b[i];
}
System.out.println(num);
}
}