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”.
这个题目重点就是要理解它的意思，如果是一个点 . 那就是当前路径，不管，如果是两个点 .. 那就是当前路径的上一个目录。这样我们用栈来表示的话，就是如下所示
path:"/a/./b/../../c/" split:"a",".","b","..","..","c" stack:push(a), push(b), pop(b), pop(a), push(c) --> c明白这个之后就一目了然了，就是注意返回的时候如果是”/”或者”/../”这种情形就行。
public String simplifyPath(String path) { String res = ""; String[] arrs = path.split("/"); Stack<String> s = new Stack<String>(); for (int i = 0; i < arrs.length; i++) { if (arrs[i].equals("")) { continue; } if (!arrs[i].equals(".") && !arrs[i].equals("..")) { s.push(arrs[i]); } if (arrs[i].equals("..") && !s.isEmpty()) { s.pop(); } } if (s.isEmpty()) return "/"; while (!s.isEmpty()) res = "/" + s.pop() + res; return res; }另一种链表的做法
public String simplifyPath1(String path) { String result = "/"; String[] stubs = path.split("/+"); ArrayList<String> paths = new ArrayList<String>(); for (String s : stubs){ if(s.equals("..")){ if(paths.size() > 0){ paths.remove(paths.size() - 1); } } else if (!s.equals(".") && !s.equals("")){ paths.add(s); } } for (String s : paths){ result += s + "/"; } if (result.length() > 1) result = result.substring(0, result.length() - 1); return result; }