LeetCode OJ: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".

算法思想：用栈做，注意多种情况

class Solution {public:    string simplifyPath(string path) {        stack<string> st;        string str;        for(int i=0;i<path.size();i++){            if(path[i]=='/'){                if(str==".."){                    if(!st.empty())st.pop();                }                else if(str!="."&&str!="")                    st.push(str);                str="";            }            else str+=path[i];        }        if(str==".."){            if(!st.empty())st.pop();        }        else if(str!="."&&str!="")st.push(str);        if(st.empty())return "/";        str="";        while(!st.empty()){            str="/"+st.top()+str;            st.pop();        }        return str;    }};