https://web.mit.edu/sp.268/www/rubik.pdf
Introduction to Group Theory and Permutation Puzzles March 17, 2009
Introduction
Almost everyone has tried to solve a Rubik’s cube. The first attempt often ends in vain with only a jumbled mess of colored cubies (as I will call one small cube in the bigger Rubik’s cube) in no coherent连贯的 order. Solving the cube becomes almost trivial once a certain core set of algorithms, called macros, are learned. Using basic group theory, the reason these solutions are not incredibly difficult to find will become clear.