| Simplify Path |

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.

“/a/./” –> means stay at the current directory ‘a’

“/a/b/..” –> means jump to the parent directory from ‘b’ to ‘a’

”////” –> consecutive multiple ‘/’ are a valid path, they are equivalent to single “/”.

Notes

1. Split string input with .split(“/”)
2. Loop through the splitted string array
3. Use stack to keep track of each element
4. Only add to stack if it’s anything other than [.. or / or .]
5. If we encounter .., check if stack has any element and pop last one
6. Finally add to stringbuilder using / before every stack read using for loop(if u use for loop, we can read from beginning to top of stack)

Time Complexity - O(n) | Space Complexity - O(n)

class Solution {
    public String simplifyPath(String path) {
        StringBuilder builder = new StringBuilder();
        Stack<String> stack = new Stack<>();
        String[] components = path.split("/");

        for (String dir : components) {
            if (dir.equals(".") || dir.isEmpty()) {
                continue;
            } else if (dir.equals("..")) {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            } else {
                stack.add(dir);
            }
        }

        for (String dir : stack) {
            builder.append("/");
            builder.append(dir);
        }

        return builder.length() > 0 ? builder.toString() : "/";
    }
}