如何在不生成镜像排列的情况下排列整数数组(Java)

public class Permutation {
    public static void permute(int[] nums) {
        permuteHelper(nums, 0);
    }

    private static void permuteHelper(int[] nums, int start) {
        if (start == nums.length - 1) {
            // 已经生成了一个完整的排列，输出结果
            printArray(nums);
            return;
        }

        for (int i = start; i < nums.length; i++) {
            swap(nums, start, i); // 交换元素
            permuteHelper(nums, start + 1); // 递归调用下一层
            swap(nums, start, i); // 恢复交换
        }
    }

    private static void swap(int[] nums, int i, int j) {
        int temp = nums[i];
        nums[i] = nums[j];
        nums[j] = temp;
    }

    private static void printArray(int[] nums) {
        for (int num : nums) {
            System.out.print(num + " ");
        }
        System.out.println();
    }

    public static void main(String[] args) {
        int[] nums = {1, 2, 3};
        permute(nums);
    }
}