Implement Unix-like `cd` Command (with Symlink Follow-up)

Problem: Implement a Unix-like cd Command (with Symlink Follow-up) Implement a simplified cd (change directory). Given the current working directory cwd and a target path, return the resulting directory after applying cd. You must support at least the following path semantics: Absolute paths: start with /, e.g. /a/b. Relative paths: e.g. a/b, interpreted relative to cwd. Special segments: . means current directory (ignore). .. means parent directory (staying at / if already at root). Redundant slashes should be treated as a single separator (e.g. /a//b/ equals /a/b). Output: a normalized absolute path string (starts with / and does not end with / unless it is the root). Follow-up: Add Symbolic Links (symlinks) The system has a symlink mapping links where links[src] = dst. While resolving a path, whenever the resolution reaches src, it should jump to dst (dst may be absolute or relative). Describe or implement how to handle: symlinks appearing in the middle of a path multi-hop symlink chains symlink cycles (e.g., /a -> /b, /b -> /a) Constraints Total path length L: 1 <= L <= 1e5 Number of symlinks M: 0 <= M <= 1e5 Example Tests cwd=/a/b, path=../c → /a/c cwd=/, path=../../x → /x cwd=/a, path=/a//b/./c → /a/b/c (with symlink) links[/x]=/a/b, cwd=/, path=/x/../c → /a/c (cycle) links[/a]=/b, links[/b]=/a, cwd=/, path=/a → must detect/avoid infinite loops (return an error or follow interviewer’s spec) Example Input cwd=/a/b path=../c links=0 Output /a/c