71. Simplify Path
Given an absolute path for a file (Unix-style), simplify it.
For example,
path = "/home/"
, => "/home"
path = "/a/./b/../../c/"
, => "/c"
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"
.
java的split函数,只要separator的前“或者”后没有“别的”字符串就会返回一个空。
linux系统当中,多余两个的点会被当作普通路径处理。
public class Solution { public String simplifyPath(String path) { if (path.length() == 0) { return ""; } String[] strs = path.split("/"); StringBuilder result = new StringBuilder(); LinkedList<String> stack = new LinkedList<String>(); for (String string : strs) { switch (string) { case "": stack.offer("/"); break; case ".": break; case "..": while (!stack.isEmpty() && stack.removeLast().equals("/")); break; default: stack.offer(string); } } if (path.charAt(0) == '/') { result.append('/'); } while (!stack.isEmpty()) { String string = stack.removeFirst(); if (!string.equals("/")) { result.append(string); result.append('/'); } } int ll = result.length(); if (ll > 1 && result.charAt(ll - 1) == '/') { result.deleteCharAt(ll - 1); } return result.toString(); } }