1+ /*
2+ Author: Andy, nkuwjg@gmail.com
3+ Date: Jan 11, 2015
4+ Problem: Simplify Path
5+ Difficulty: Easy
6+ Source: https://oj.leetcode.com/problems/simplify-path/
7+ Notes:
8+ Given an absolute path for a file (Unix-style), simplify it.
9+
10+ For example,
11+ path = "/home/", => "/home"
12+ path = "/a/./b/../../c/", => "/c"
13+
14+ Corner Cases:
15+ Did you consider the case where path = "/../"?
16+ In this case, you should return "/".
17+ Another corner case is the path might contain multiple slashes '/' together, such as "/home//foo/".
18+ In this case, you should ignore redundant slashes and return "/home/foo".
19+
20+ Solution: Add an additional '/' at the end of 'path' for simply detecting the end.
21+ */
22+ public class Solution {
23+ public String simplifyPath (String path ) {
24+ if (path .length ()==0 )return "/" ;
25+ if (path .charAt (0 )!='/' )return "/" ;
26+ ArrayList <String >dirs =new ArrayList <String >();
27+ String []str =path .split ("/" );
28+ for (int i =0 ;i <str .length ; ++i ) {
29+ if ((i ==0 ||i ==str .length -1 ) &&str [i ].compareTo ("" ) ==0 )continue ;
30+ if (str [i ].compareTo (".." ) ==0 ) {
31+ if (dirs .isEmpty () ==false ) {
32+ dirs .remove (dirs .size () -1 );
33+ }
34+ }else if ((str [i ].compareTo ("." ) !=0 ) && (str [i ].compareTo ("" ) !=0 )) {
35+ dirs .add (str [i ]);
36+ }
37+ }
38+ if (dirs .isEmpty () ==true )return "/" ;
39+ StringBuilder res =new StringBuilder ();
40+ for (int i =0 ;i <dirs .size (); ++i ) {
41+ res .append ("/" );
42+ res .append (dirs .get (i ));
43+ }
44+ return res .toString ();
45+ }
46+ }
