71. Simplify Path

class Solution {
public:
    string simplifyPath(string path) {
        vector<string> ret;
        stringstream ss(path);
        string s;
        string retS="";
        while(getline(ss,s,'/')){
            if(s=="."||s==""||(s==".."&&ret.empty())) continue;
            if(s==".." && !ret.empty()){
                ret.pop_back();
            }else{
                ret.push_back(s);
            }
        }
        if(ret.empty()){
            return "/";
        }else{
            for(string s : ret){
                retS+="/"+s;
            }
        }
        return retS;

    }
};

• http://www.cnblogs.com/grandyang/p/4347125.html