class Solution { public: string simplifyPath(string path) { string ans; istringstream iss(path); vector<string> stack; for (string dir; getline(iss, dir, '/');) { if (dir.empty() || dir == ".") continue; if (dir == "..") { if (!stack.empty()) stack.pop_back(); } else { stack.push_back(dir); } } for (const string& s : stack) ans += "/" + s; return ans.empty() ? "/" : ans; } };