Stair-climbing puzzle: Difference between revisions

=={{header|Python}}==

=== Iterative ===

<lang python>def step_up1()

"Straightforward implementation: keep track of how many level we

need to ascend, and stop when this count is zero."

deficit = 1

while deficit > 0:

if step():

deficit -= 1

else:

deficit += 1</lang>

=== Recursive ===

This satisfies Chung-chieh's challenge to avoid using numbers. Might blow the stack as

''p'' approaches 0.5.

<lang python>def step_up2():

"No numbers."

if not step():

step_up2() # undo the fall

step_up2() # try again</lang>