Leetcode Simplify Path

题目：

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

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

Corner Cases:

• Did you consider the case where path = "/../"?
  In this case, you should return "/".
• Another corner case is the path might contain multiple slashes '/' together, such as "/home//foo/".
  In this case, you should ignore redundant slashes and return "/home/foo".

解题：

用栈可以搞，一个点不用管，两个点pop，最后再逆序输出

代码：

class Solution {public:    string simplifyPath(string path) {        stack<string> s;        int pos = 0        while(1) {            string tmp = check(path, pos);            if(tmp == "") break;            if(tmp == ".") continue;            if(tmp == "..") {                if(!s.empty())                    s.pop();            }            else                s.push(tmp);        }        if(s.empty()) return "/";        Print(s);        return ans;    }private:    string ans;    string check(string path, int &pos) {        while(path[pos] == '/') pos ++;        string rec;        int i;        for(i = pos; i < path.size() && path[i] != '/'; i ++)            rec += path[i];        pos = i;        return rec;    }    void Print(stack<string> s) {        if(s.empty()) return ;        string top = s.top();        s.pop();        Print(s);        ans += '/';        ans += top;    }};