Python: Recursive function to find the largest number in the list

Question

I\'m trying to do a lab work from the textbook Zelle Python Programming

The question asked me to \"write and test a recursive function max() to find the

Answer 1

Here is my answer, with a one line of code :))

def max_value(n_list):
    return n_list[0] if len(n_list) == 1 else max(n_list[0], max_value(n_list[1:]))

Answer 2

One simple way would be to sort the list first then use indexing.

Here's a function that would work:

a = [1,233,12,34]

def find_max(a):
    return sorted(a)[-1]

Answer 3

These solutions fail after certain list size.

This is a better version:

def maximum2(a, n):
    if n == 1:
        return a[0]
    x = maximum2(a[n//2:], n - n//2)
    return x if x > a[0] else a[0]
def maximum(a):
    return maximum2(a, len(a))

maximum(range(99999))


>>> 99998

Answer 4

def Max(lis,maxx=-float("inf")):

    if len(lis) == 1:            #only one element in lis
        return maxx if maxx>lis[0] else lis[0]  #return lis[0] if it's greater than maxx

    else:
        m=lis[0] if lis[0]>maxx else maxx  # m = max(lis[0],maxx)
        return Max(lis[1:],m)              #call Max with lis[1:] and pass 'm' too

print Max([1,2,39,4,5,6,7,8]) #prints 39
print Max([1,2,3,4,5,6,7,8]) #prints 8   

Answer 5

def find_max(arr):
  """find maximum number in array by recursion"""
  if arr == []: # if its an empty array
    return 0
  if len(arr) == 1: # if array has only one element
    return arr[0]
  else: # get max of first item compared to other items recursively
    return max(arr[0], find_max(arr[1:])) # 1: means all other excluding 0th element

def main():
  print(find_max([2,3,5,6,7,1])) # will print max - 7

if __name__ == "__main__":
  main()

Answer 6

def getMaxNumber(numbers): 
    return 'N.A' if len(numbers) == 0 else max(numbers)