Simplify Path

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

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

  • 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". 
     1 public class Solution {
 2    public String simplifyPath(String path) {
 3        int len = path.length();
 4        if(len<=0) return "";
 5        int i=0;
 6        Stack<String> stack = new Stack<String> ();
 7        while(i<len){
 8            while(i<len && path.charAt(i)=='/'){
 9                i++;
10            }
11            if(i==len)break;
12            int start = i;
13            while(i<len && path.charAt(i)!='/'){
14                i++;
15            }
16            int end = i;
17            String cur = path.substring(start,end);
18            if(cur.equals("..") ){
19               if( !stack.isEmpty()) //be carefull about here can't code like if(cur.equals("..") && !stack.isEmpty())
20                stack.pop();
21            }
22            else if(!cur.equals(".")){
23                stack.push(cur);
24            }
25        }
26        if(stack.isEmpty()) return "/";
27        StringBuilder sb = new StringBuilder();
28        while(!stack.isEmpty()){
29            
30            sb.insert(0,stack.pop());
31            sb.insert(0,'/');
32        }
33        return sb.toString();
34    }
35 }
    View Code

     // don't forget

posted @ 2014-02-19 05:26  krunning  阅读(262)  评论(0)  编辑  收藏  举报