leetcode-----46. 全排列

• 链接：https://leetcode-cn.com/problems/permutations/

代码

class Solution {
public:
    vector<vector<int>> ans;
    vector<int> path;
    vector<bool> st;

    vector<vector<int>> permute(vector<int>& nums) {
        int n = nums.size();
        path = vector<int>(n);
        st = vector<bool>(n);
        
        dfs(nums, 0);
        return ans;    
    }

    void dfs(vector<int>& nums, int u) {
        if (u == nums.size()) {
            ans.push_back(path);
            return;
        }

        for (int i = 0; i < nums.size(); ++i) {
            if (st[i] == false) {
                path[u] = nums[i];
                st[i] = true;
                dfs(nums, u + 1);
                st[i] = false;
            }
        }
    }
};