Question

I am new to python and I am having a problem. I want to write a recursive function that takes two inputs (integers) and subtracts the second from the first, until the first is less than the second, and calculates the # of time it subtracts before being less.

This is what I have so far, but I am having problems getting the function to repeat the subtraction of the second from the first;

def div(first,sec):
    if first > sec:
        return div((first - sec),sec) + first

    else:
        return 0

Answer 1

## naive recursion
def div(a, b):
    if (a >= b):
        return div(a - b, b) + 1
    else: return 0

try:
    print div(5678, 3)
except Exception as e:
    print e  ## maximum recursion depth exceeded


## less naive recursion with trampolines
## see https://gist.github.com/802557 for details/explanations
def trampoline(f):
    def _(*args):
        result = f(*args)
        while callable(result):
            result = result()
        return result
    return _

def div_func(a, b, acc=0):
    if (a >= b):
        return lambda: div_func(a - b, b, acc + 1)
    else: return acc

div2 = trampoline(div_func)

## ok
print div2(5678, 3)