题解 | #字符串的排列#

class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param str string字符串 
     * @return string字符串vector
     */
    void recursion(vector<string>&res,string& str,vector<int>&vis,string &tmp)
    {
        if(tmp.size()==str.size())
        {
            res.push_back(tmp);
        }
        for(int i =0;i<str.size();i++)
        {
            if(vis[i])
                continue;
            if(i>0&&str[i]==str[i-1]&&!vis[i-1])
                continue;
            vis[i] = 1;
            tmp+=str[i];
            recursion(res,str,vis,tmp);
            //回溯
            vis[i] = 0;
            tmp.pop_back();
        }
    }

    vector<string> Permutation(string str) {
        // write code here
        sort(str.begin(),str.end());
        vector<int>vis(str.size(),0);
        string tmp;
        vector<string>res;
        recursion(res,str,vis,tmp);
        return res;
    }
};