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 dfs(vector<string> & result,string ¤t,string& str,vector<bool>& vis)
     {
        if(current.size()==str.size())
        {
            result.push_back(current);
            return;
        }

        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]=true;
            current.push_back(str[i]);
            dfs(result,current,str,vis);
            current.pop_back();
            vis[i]=false;
            
        }
     }
    vector<string> Permutation(string str) {
        if(str.size()==0) return {""};
        // write code here
        vector<string> result;
        string current;
        vector<bool> vis(str.size(),false);

        sort(str.begin(),str.end());
        dfs(result,current,str,vis);
        return result;
    }
};