71. Simplify Path
Given an absolute path for a file (Unix-style), simplify it. Or in other words, convert it to the canonical path.
In a UNIX-style file system, a period . refers to the current directory. Furthermore, a double period .. moves the directory up a level. For more information, see: Absolute path vs relative path in Linux/Unix
Note that the returned canonical path must always begin with a slash /, and there must be only a single slash / between two directory names. The last directory name (if it exists) must not end with a trailing /. Also, the canonical path must be the shortest string representing the absolute path.
Example 1:
Input: "/home/"
Output: "/home"
Explanation: Note that there is no trailing slash after the last directory name.
Example 2:
Input: "/../"
Output: "/"
Explanation: Going one level up from the root directory is a no-op, as the root level is the highest level you can go.
Example 3:
Input: "/home//foo/"
Output: "/home/foo"
Explanation: In the canonical path, multiple consecutive slashes are replaced by a single one.
Example 4:
Input: "/a/./b/../../c/"
Output: "/c"
Example 5:
Input: "/a/../../b/../c//.//"
Output: "/c"
Example 6:
Input: "/a//b////c/d//././/.."
Output: "/a/b/c"
class Solution { public String simplifyPath(String path) { String[] strs = path.split("/"); ArrayList<String> list1 = new ArrayList<String>(); for(int i = 0; i < strs.length; i++){ //将空字符串（由类似这种"/a//c"的字符串产生）和 "." （"."代表当前目录不影响路径）去掉，保存到 list1 if (strs[i].isEmpty() || strs[i].equals(".")) { continue; } list1.add(strs[i]); } ArrayList<String> list2 = new ArrayList<String>(); for(int i = 0; i < list1.size(); i++){ if(list1.get(i).equals("..")){ if(!list2.isEmpty()){ list2.remove(list2.size() - 1); } } else list2.add(list1.get(i)); } String res = String.join("/",list2); res = "/" + res; return res; } }
这种题真是索然无味
