2022.4.20-----leetcode. three hundred and eighty-eight

  public static int lengthLongestPath(String input) {
        String[] dirs=input.split("\n");// Division 
        Deque<Integer> stk=new ArrayDeque<>();
        int cur=0;// Current path length 
        int max=0;// Maximum path length 
        for (String dir : dirs) {
            int layer=0;// There are several '\t' Represents the level of the directory 
            int i;
            for (i = 0; dir.charAt(i)=='\t' ; i++) {
                layer++;
            }
            int len=dir.substring(i).length();// The length of the directory name is 
            // Stack according to the layer of the directory , And update the cur
            int n=stk.size();// It's on the second day n-1 layer 
            for (int j = 0; j < n-layer; j++) {
                cur-=stk.pollLast()+1;
            }
            stk.offer(len);// Add this directory 
            cur+=len+1;
            // Maximum length of file record encountered 
            if(dir.contains("."))
                max=Math.max(max,cur);
        }
        if(max==0)// No files 
            return max;
        return max-1;// Not before the first directory '/'

    }