如何删除C++中的重复排列

#include <iostream>
#include <vector>
#include <algorithm>

void generatePermutations(std::vector<int>& nums, std::vector<int>& permutation, std::vector<bool>& used, std::vector<std::vector<int>>& result) {
    if (permutation.size() == nums.size()) {
        result.push_back(permutation);
        return;
    }

    for (int i = 0; i < nums.size(); i++) {
        if (used[i] || (i > 0 && nums[i] == nums[i - 1] && !used[i - 1])) {
            continue;
        }

        used[i] = true;
        permutation.push_back(nums[i]);
        generatePermutations(nums, permutation, used, result);
        permutation.pop_back();
        used[i] = false;
    }
}

std::vector<std::vector<int>> permuteUnique(std::vector<int>& nums) {
    std::sort(nums.begin(), nums.end());
    std::vector<std::vector<int>> result;
    std::vector<int> permutation;
    std::vector<bool> used(nums.size(), false);
    generatePermutations(nums, permutation, used, result);
    return result;
}

int main() {
    std::vector<int> nums = {1, 1, 2};
    std::vector<std::vector<int>> result = permuteUnique(nums);

    for (const auto& permutation : result) {
        for (const auto& num : permutation) {
            std::cout << num << " ";
        }
        std::cout << std::endl;
    }

    return 0;
}