Given a string path, which is an absolute path (starting with a slash '/') to a file or directory in a Unix-style file system, convert it to the simplified canonical path.
In a Unix-style file system, a period '.' refers to the current directory, a double period '..' refers to the directory up a level, and any multiple consecutive slashes (i.e. '//') are treated as a single slash '/'. For this problem, any other format of periods such as '...' are treated as file/directory names.
The canonical path should have the following format:
- The path starts with a single slash '/'.
- Any two directories are separated by a single slash '/'.
- The path does not end with a trailing '/'.
- The path only contains the directories on the path from the root directory to the target file or directory (i.e., no period '.' or double period '..')
- Return the simplified canonical path.
Example 1:
Input: path = "/home/"
Output: "/home"
Explanation: Note that there is no trailing slash after the last directory name.
Example 2:
Input: path = "/../"
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: path = "/home//foo/"
Output: "/home/foo"
Explanation: In the canonical path, multiple consecutive slashes are replaced by a single one.
Constraints:
- 1 <= path.length <= 3000
- path consists of English letters, digits, period '.', slash '/' or '_'.
- path is a valid absolute Unix path.
class Solution {
public String simplifyPath(String path) {
Deque<String> stack = new LinkedList<>();
for(String s: path.split("/")){
if(s.equals("..") ){
stack.poll();
}else if(!s.equals("") && !s.equals(".")){
stack.push(s);
}
}
StringBuilder sb = new StringBuilder();
if(stack.size() == 0){
return "/";
}
while(stack.size() != 0){
sb.append("/").append(stack.pollLast());
}
return sb.toString();
}
}