例如,字符串“25482”,如果按1组来分需要得到如下结果:x25482如果按2组来分得到如下结果:x2548x2,x254x82,x25x482,x2x5482如果按3组来分需要得到如下结果:x254x8x2,x25x4x82,x25x48x2,x2x5x482,x2x54,x82,x2x548x2