47.全排列II

题目
给定一个可包含重复数字的序列，返回所有不重复的全排列。

示例:****
输入: [1,1,2]
输出:
[
[1,1,2],
[1,2,1],
[2,1,1]
]

思路：
递归方法同46.全排列， 删除重复项的方法同40.组合总和II

#include <vector>
using namespace std;
class Solution {
private:
    void swap (vector<int>& nums, int begin, int end)
    {
        int temp = nums[begin];
        nums[begin] = nums[end];
        nums[end] = temp;
    }
    void findPermuteUnique(vector<int>& nums, vector<vector<int>>& result, int begin, int end)
    {
        if(begin == end)
        {
            vector<vector<int>>::iterator flag;
            flag = find(result.begin(), result.end(), nums);
            if (flag == result.end())
            {
                result.push_back(nums);
                return;
            }
        }

        for(int i = begin; i <= end; i ++)
        {
            swap(nums, i, begin);
            findPermuteUnique(nums, result, begin + 1, end);
            swap(nums, i, begin);
        }

    }
public:
    vector<vector<int>> permuteUnique(vector<int>& nums) {
        vector<vector<int>> result;
        vector<int> temp;
        int end = nums.size() - 1;
        findPermuteUnique(nums, result, 0, end);
        return result;
    }
};

int main(int argc, char* argv[])
{
    vector<int> test = {1, 1, 2};
    auto res = Solution().permuteUnique(test);
    return 0;
}