Just to add to what Watermom said, while your pool is at shock level, make sure and brush it, especially in the areas where there is visible algae. That will help make sure that you're getting maximum exposure of chlorine to the algae and maybe stop it from keeping a foothold in the pool after your chlorine levels come back down. After you get rid of the algae, you need to make sure that your chlorine doesn't drop below 3 ppm (and with the very warm temps I would keep it closer to 5) to keep it from coming back.

Janet