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

For example,

path = "/home/", => "/home"

path = "/a/./b/../../c/", => "/c"

 

注意：题目中已限定是absolute path - contains the root directory and all other subdirectories in which a file or folder is contained.

class Solution {public:    string simplifyPath(string path) {        stack
     
       pathStack;        string splitPath = path;        string curPath;        string ret="";        int pos = 0;//absolute path, so path[0]=='/'        while(pos!=string::npos && pos+1 < splitPath.length()){            splitPath = splitPath.substr(pos+1);             pos = splitPath.find_first_of('/');            if(pos!=0){ //ignore second '/'                curPath = splitPath.substr(0,pos);                                if(curPath=="."){
   //ignore './'                                    }                else if(curPath==".." ){ //ignore '/..'                    if(!pathStack.empty()) pathStack.pop();                }                else{ //除了"."以及".."以外的都是文件名，比如"..."                    pathStack.push(curPath);                }            }        }                if(pathStack.empty()) return "/";        while(!pathStack.empty()){            ret = "/" + pathStack.top() + ret;            pathStack.pop();        }        return ret;    }};