【leetcode】Simplify Path

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".

 

用一个堆栈来模拟路径的行为，遇到"."不操作，遇到".."退栈，其他情况都压入堆栈。

程序中先把路径分割出来，然后再处理

 

class Solution {

public:
    string simplifyPath(string path) {
        vector<string> spl;
        spliceStr(path,spl);   
        vector<string> stk;
        for(int i=0;i<spl.size();i++)
        {
            if(spl[i]=="..")
            {
                if(!stk.empty())
                {
                  stk.pop_back();  
                }
            }
            else if(spl[i]==".")
            {
                continue;
            }
            else
            {
                stk.push_back(spl[i]);
            }
        }
        string result="";
        for(int i=0;i<stk.size();i++)
        {
            result+="/"+stk[i];
        }
        if(result=="")
        {
            result="/";
        }
        return result;
    }

   

   

    void spliceStr(string &path,vector<string> &result)
    {
        int pre_index=0;
        string tmp;
        for(int i=0;i<path.size();i++)
        {
            if(path[i]=='/')
            {
                tmp=path.substr(pre_index,i-pre_index);
                if(tmp!="")
                {
                   result.push_back(tmp);
                }
                pre_index=i+1;
            }
        }

        if(pre_index<path.size())
        {
            tmp=path.substr(pre_index,path.size()-pre_index);
            if(tmp!="")
            {
                result.push_back(tmp);
            }
        }
    }
};