public static void main(String[] args) {

LongestAbsoluteFilePath la = new LongestAbsoluteFilePath();

String input = "dir\n\tsubdir1\n\t\tfile1.ext\n\t\tsubsubdir1\n\tsubdir2\n\t\tsubsubdir2\n\t\t\tfile2.ext";

int result = la.lengthLongestPath("dir\n file.txt".replaceAll(" ", "\t"));

System.out.println(result);

}

public int lengthLongestPath(String input) {

String[] tokens = input.split("\n");

Stack<Integer> pathLen = new Stack<> ();

int result = 0;

for(String s: tokens) {

int level = s.lastIndexOf("\t") + 2;

// System.out.println(level);

while(!pathLen.empty() && pathLen.size() >= level) pathLen.pop();

int currPathLen = pathLen.empty()? (s.length() - level + 2): (pathLen.peek() + s.length() - level + 2);

pathLen.push(currPathLen);

// System.out.println(pathLen);

if(s.indexOf(".") >= 0) result = Math.max(result, currPathLen - 1);

//System.out.println(pathLen);

}

return result;

}