在java中查找数组中出现两次以上的重复元素

import java.util.HashMap;
import java.util.Map;

public class DuplicateElements {
    public static void main(String[] args) {
        int[] array = {1, 2, 3, 4, 1, 2, 5, 6, 3};
        Map<Integer, Integer> map = new HashMap<>();

        for (int num : array) {
            if (map.containsKey(num)) {
                map.put(num, map.get(num) + 1);
            } else {
                map.put(num, 1);
            }
        }

        for (Map.Entry<Integer, Integer> entry : map.entrySet()) {
            if (entry.getValue() > 1) {
                System.out.println("重复元素: " + entry.getKey());
            }
        }
    }
}

import java.util.HashSet;
import java.util.Set;

public class DuplicateElements {
    public static void main(String[] args) {
        int[] array = {1, 2, 3, 4, 1, 2, 5, 6, 3};
        Set<Integer> set = new HashSet<>();
        Set<Integer> duplicates = new HashSet<>();

        for (int num : array) {
            if (!set.add(num)) {
                duplicates.add(num);
            }
        }

        for (int duplicate : duplicates) {
            System.out.println("重复元素: " + duplicate);
        }
    }
}

public class DuplicateElements {
    public static void main(String[] args) {
        int[] array = {1, 2, 3, 4, 1, 2, 5, 6, 3};

        for (int i = 0; i < array.length - 1; i++) {
            for (int j = i + 1; j < array.length; j++) {
                if (array[i] == array[j]) {
                    System.out.println("重复元素: " + array[i]);
                }
            }
        }
    }
}