目錄

1 問題描述

2 解決方案

1 問題描述

2 解決方案

具體代碼如下：

import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

public class Main {
    public static int n;
    
    public void getResult() {
        ArrayList
 
<Integer> result = new ArrayList<Integer>();
        for(int i = 10000;i < 1000000;i++) {
            String temp = i + "";
            if(temp.length() == 5) {
                if(temp.charAt(0) == temp.charAt(4) && temp.charAt(1)
                        == temp.charAt(3)) {
                    
 
int num = i % 10 * 2 + i / 10 % 10 * 2 + i / 100 % 10;
                    if(num == n)
                        result.add(i);
                }
            } else if(temp.length() == 6) {
                if(temp.charAt(0) == temp.charAt(5) && temp.charAt(1)
                        == temp.charAt(4) && temp.charAt(2) == temp.charAt(3)) {
                    int num = i % 10 * 2 + i / 10 % 10 * 2 + i / 100 % 10 * 2;
                    if(num == n)
                        result.add(i);
                }
            }
        }
        if(result.size() == 0)
            System.out.println("-1");
        else {
            Collections.sort(result);
            for(int i = 0;i < result.size();i++)
                System.out.println(result.get(i));
        }
    }
        
    public static void main(String[] args) {
        Main test = new Main();
        Scanner in = new Scanner(System.in);
        n = in.nextInt();
        test.getResult();
    }
}

算法筆記_181:歷屆試題 回文數字(Java)