使用ArrayList和用户输入在不同的索引处查找相同的数字

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

public class ArrayListExample {
    public static void main(String[] args) {
        ArrayList<Integer> numbers = new ArrayList<>();
        ArrayList<Integer> matchingIndexes = new ArrayList<>();

        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入数字个数：");
        int count = scanner.nextInt();

        System.out.println("请输入数字：");
        for (int i = 0; i < count; i++) {
            int num = scanner.nextInt();
            numbers.add(num);
        }

        for (int i = 0; i < numbers.size(); i++) {
            int currentNum = numbers.get(i);
            for (int j = i + 1; j < numbers.size(); j++) {
                int nextNum = numbers.get(j);
                if (currentNum == nextNum) {
                    matchingIndexes.add(j);
                }
            }
        }

        if (matchingIndexes.isEmpty()) {
            System.out.println("没有找到相同的数字。");
        } else {
            System.out.println("找到相同的数字的索引位置：");
            for (int index : matchingIndexes) {
                System.out.println(index);
            }
        }
    }
}