Resolve a Unix cd Path Against a Current Working Directory

Implement Unix-style path resolution. Given a current working directory cwd (guaranteed to be absolute) and a path argument path to a cd command, return the normalized absolute path after executing cd path. Rules: If path starts with /, it is absolute and cwd is ignored. Otherwise, path is relative to cwd. . means the current directory; .. means the parent directory. Applying .. at root stays at root. Repeated / characters are equivalent to one /. Directory names consist of letters, digits, _, -, and .. Only complete components . and .. have special meaning. The result must have no trailing slash unless it is /. Input Format Two lines: cwd, then path. Example Input /home/user/projects ../../docs/./api Output /home/docs/api Constraints The combined path length is at most 2 * 10^5. Example Input /home/user/projects ../../docs/./api Output /home/docs/api