Swift Puzzle (Numbers)

滑動拼圖，打亂數字

A sliding puzzle, sliding block puzzle, or sliding tile puzzle is a combination puzzle that challenges a player to slide (frequently flat) pieces along certain routes (usually on a board) to establish a certain end-configuration. The pieces to be moved may consist of simple shapes, or they may be imprinted with colors, patterns, sections of a larger picture (like a jigsaw puzzle), numbers, or letters.

Rules of this game are very simple - we are sliding (←, →, ↑ , ↓) tiles to reach the final state in which all numbers are in order with ‘1’ in the top left corner of the board.