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

For example,

path = "/home/", => "/home"

path = "/a/./b/http://www.cnblogs.com/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".

用栈来做

1 class Solution { 2 public: 3     string simplifyPath(string path) { 4         // Start typing your C/C++ solution below 5         // DO NOT write int main() function 6         stack
      
        s; 7         string str; 8         for(int i = 0; i < path.size(); i++) 9         {10             if (path[i] == '/')11             {12                 if (str == "..")13                 {14                     if (!s.empty())15                         s.pop();16                 }17                 else if (str != "." && str != "")18                 {19                     s.push(str);20                 }21 22                 str = "";23             }24             else25             {26                 str += path[i];27             }28         }29         30         if (str == "..")31         {32             if (!s.empty())33                 s.pop();34         }35         else if (str != "." && str != "")36             s.push(str);37         38         if (s.empty())39             return "/";40         41         string ret;42         while(!s.empty())43         {44             ret = "/" + s.top() + ret;45             s.pop();46         }47         48         return ret;49     }50 };