For example,
path = "/home/", => "/home"
path = "/a/./b/../../c/", => "/c"
[分析] 思路很简单,遇到“.”跳过,遇到“..”删除其前面一级目录,使用堆栈来删除前一级目录的想法很妙(要是我自己想出来就好了~)。 另外分割字符串来处理的思路也要用心体会,联系reverse-words-in-a-string 一题:
https://leetcode.com/problems/reverse-words-in-a-string/
public String simplifyPath(String path) { if (path == null || path.length() == 0) return path; String[] dirs = path.split("/"); LinkedList<String> stack = new LinkedList<String>(); for (String dir : dirs) { if (dir.isEmpty() || dir.equals(".")) continue; else if (dir.equals("..")) { if (!stack.isEmpty()) stack.pop(); } else { stack.push(dir); } } if (stack.isEmpty()) { return "/"; } StringBuilder newpath = new StringBuilder(); while (!stack.isEmpty()) { newpath.insert(0,"/" + stack.pop()); } return newpath.toString(); }