71.简化路径

Simplify Path

问题描述：

Given an absolute path for a file (Unix-style), simplify it.

For example,
path = “/home/”, => “/home”
path = “/a/./b/../../c/”, => “/c”

测试代码（c++）：

class Solution {public:    string simplifyPath(string path) {        vector<string> st;        vector<string> nodes;        string result;        split(path, '/', nodes);        for(auto node : nodes) {            //empty or only '.' path no change            if(node == "" || node == ".")  continue;            //go back to the upper directory            if(node == ".." && !st.empty())  st.pop_back();            //push back the current directory            else if(node != "..")  st.push_back(node);        }        for(auto it : st) result += "/" + it;        return result.empty() ? "/" : result;    }    void split(string s, char delim, vector<string>& nodes) {        string temp;        stringstream ss(s);        while(getline(ss, temp, delim)) {            nodes.push_back(temp);        }    }};

性能：

参考答案（python）：

class Solution(object):    def simplifyPath(self, path):        places = [p for p in path.split("/") if p!="." and p!=""]        stack = []        for p in places:            if p == "..":                if len(stack) > 0:                    stack.pop()            else:                stack.append(p)        return "/" + "/".join(stack)

性能：