   updateGridColors();
   leds.write(colors, STRIP_LENGTH);
 }
+

const int GRIDSIZE = 7;
const int STRIP_LENGTH = GRIDSIZE * GRIDSIZE;

PololuLedStrip<2> leds;
rgb_color colors[STRIP_LENGTH];

const int SWITCH_ON = 1;

  37, 38, 39, 40, 41, 42, 43,
  44, 45, 46, 47, 48, 49, 50,
};

const int E = 99; // Empty cell. Everything else is a wall.
const int PUZZLE[] = {
