[LeetCode]Simplify Path

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

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

click to show corner cases.

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".

思考：不断提交修改。。

class Solution {

public:

    string simplifyPath(string path) {

        // ..上一级目录

        // .当前目录

        // 根目录下..和.相同

        string ans="";

        vector<string> p; //记录每一级目录

        string temp;

        int len1=path.size();

        int i;

        for(i=0;i<len1;i++)

        {

            if(path[i]=='/')

            {

                if(temp=="") continue; 

                else if(temp=="..") 

                {

                    if(p.empty()) temp=""; //根目录

                    else 

                    {

                        p.pop_back(); //返回上一级目录

                        temp="";

                    }

                }

                else if(temp==".") temp="";

                else 

                {

                    p.push_back(temp);

                    temp="";

                }

            }

            else temp+=path[i];

        }

        if(temp!=""&&temp!=".") 

        {

            if(temp=="..")

            {

                if(!p.empty()) 

                p.pop_back();

            }

            else p.push_back(temp);

        }

        int len2=p.size();

        if(len2==0) return "/";

        for(i=0;i<len2;i++) ans+='/'+p[i];

        return ans;

    }

};