發送短信 : The graph relabeling problem and its variants

  _  _     ______     _____    ______            
 | \| ||  /_   _//   / ___//  /_   _//   ____    
 |  ' ||   -| ||-    \___ \\   -| ||-   |    \\  
 | .  ||   _| ||_    /    //   _| ||_   | [] ||  
 |_|\_||  /_____//  /____//   /_____//  |  __//  
 `-` -`   `-----`  `-----`    `-----`   |_|`-`   
                                        `-`