/**
 * 71. 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.
 *
 * In a Unix-style file system, a period '.' refers to the current directory, a double period '..' refers to the directory up a level, and any multiple consecutive slashes (i.e. '//') are treated as a single slash '/'. For this problem, any other format of periods such as '...' are treated as file/directory names.
 *
 * The canonical path should have the following format:
 *
 * The path starts with a single slash '/'.
 * Any two directories are separated by a single slash '/'.
 * The path does not end with a trailing '/'.
 * The path only contains the directories on the path from the root directory to the target file or directory (i.e., no period '.' or double period '..')
 * Return the simplified canonical path.
 *
 * Refer: 220106-CN.cpp
 */