Question: If you have a N steps staircase and you are standing at 1 step now you have options to step up to 2step or you can skip one step and go to 3rd step... so at ith step you have a option to go to i+1 step or i+2 step. So how many ways you can climb the stairs?

Solution: We can restate the problem in terms of fibbonaci series
n is nth stair
f(n) = f(n-1) + f(n-2)
f(1) = 0
f(2) = 1