71.Simplify Path

class Solution {
public:
    string simplifyPath(string path) {
        string res, t;
        stringstream ss(path);
        vector<string> v;
        while (getline(ss, t, '/')) {
            if (t == "" || t == ".") continue;
            if (t == ".." && !v.empty()) v.pop_back();
            else if (t != "..") v.push_back(t);
        }
        for (string s : v) res += "/" + s;
        return res.empty() ? "/" : res;
    }
};