71. Simplify Path (Stack)

標籤：

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

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

 

class Solution {public:    string simplifyPath(string path) {        stack<char> pathStack;        pathStack.push(path[0]);        for(int i =1; i<path.length(); i++)        {            if(path[i]==‘/‘)            {                if(pathStack.top() == ‘/‘) continue; //ignore second ‘/‘                else if(pathStack.top()==‘.‘) //ignore ‘./‘                {                    pathStack.pop();                }                else                {                    pathStack.push(path[i]);                }            }            else if(path[i]==‘.‘)            {                if(pathStack.top() != ‘.‘) {                    pathStack.push(path[i]);                    continue;                }                pathStack.pop(); //pop ‘/..‘中的第一個‘.‘                if(pathStack.size()==1) continue;                                pathStack.pop(); //pop ‘/..‘中的‘/‘                while(pathStack.top() != ‘/‘) pathStack.pop(); //pop ‘/..‘的上一個檔案路徑                if(pathStack.size()>1){                    pathStack.pop();                }             }            else            {                pathStack.push(path[i]);            }               }        while(pathStack.size()>1 && (pathStack.top()==‘/‘ || pathStack.top()==‘.‘)) pathStack.pop(); //path最後的‘.‘和‘/‘要去掉        //stack中剩餘的是要return的path        if(pathStack.empty()) return "/";        int len = pathStack.size();        path = path.substr(0,len);        while(!pathStack.empty())        {            path[--len]=pathStack.top();            pathStack.pop();        }        return path;    }}

 

71. Simplify Path (Stack)