double recursion

print("max=", findMax(list,0,len(list)-1)))

I've already passed the l and r while writing findMax(list, blah, blah blah).

findMax() If you look at the contents of the function itself,

# Strategy...
        lmax = findMax (list, this or that)
        rmax = findMax (list, what, what)
# Sneak...

You can see that this is how they're passing the price.

If you're curious about what kind of magic findMax() itself uses to find the maximum value, it's better to study what we call split conquest technique.