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. 

< p>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. < /span>

Example 3:

Input: "/home//foo/"

Output: "/home/foo" Explanation: In the canonical path, multiple consecutive slashes are replaced by a single one. < /pre> 
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"

< span style="color: #0000ff;">class Solution {

 public String simplifyPath(String path) {

 String[] strs = path.split("/");

 ArrayList list1 = new ArrayList();

 for(int i = 0; i ){

 //Insert an empty string (by similar to this "/a //c" string generation) and "." ("." represents The current directory does not affect the path) remove it and save it to list1

 if (strs[i].isEmpty() || strs[i].equals(".")) {

 continue;

}

 list1.add(strs[i]);

}

 ArrayList list2 = new ArrayList();

 for(int i = 0; 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;

}

}

< /p> 
This kind of question is really dull
https://leetcode.wang/leetCode-71-Simplify-Path.html

class Solution {

 public String simplifyPath(String path) {

 String[] strs = path.split("/");

 ArrayList list1 = new ArrayList();

 for(int i = 0; i ){

 //Insert an empty string (by similar to this "/a //c" string generation) and "." ("." represents The current directory does not affect the path) remove it and save it to list1

 if (strs[i].isEmpty() || strs[i].equals(".")) {

 continue;

}

 list1.add(strs[i]);

}

 ArrayList list2 = new ArrayList();

 for(int i = 0; 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;

}

}