leetcode 47 Permutations II

题目意思

求一个数组的全排列（会有重复的数字）

题解

class Solution {
public:
    
    void dfs(vector<int> nums, int st, int ed, vector<vector<int>> &res) {
        if (st == ed) {
            res.push_back(nums);
            return ;
        }
        for(int i=st; i<ed; i++) {
            if(i != st && nums[i] == nums[st]) continue;
            swap(nums[i], nums[st]);
            dfs(nums, st+1, ed, res);
        }
        return ;
    }
    
    vector<vector<int>> permuteUnique(vector<int>& nums) {
        sort(nums.begin(), nums.end());
        vector<vector<int>> res;
        dfs(nums, 0, nums.size(), res);
        return res;
    }
};