Answers for "function fibonacci python"

fibonacci sequence python

# WARNING: this program assumes the
# fibonacci sequence starts at 1
def fib(num):
	"""return the number at index `num` in the fibonacci sequence"""
    if num <= 2:
        return 1
    return fib(num - 1) + fib(num - 2)

# method 2: use `for` loop
def fib2(num):
	a, b = 1, 1
	for _ in range(num - 1):
		a, b = b, a + b
	return a


print(fib(6))  # 8
print(fib2(6))  # same result, but much faster

fibonacci python

# This function computes and returns fibonacci 
# sequence number using Dynamic Programming
def fib(num, memo{}):
	if num in memo:
	    return memo[num]
	if num <= 2:
      return 1
    
   	memo[n] = fib(num-1, memo) + fib(num-2, memo)
    return memo[n]
	
  	"""
	  	params:
	    	int num: index of fibonacci sequence
	        dict memo: This object is needed to perform dynamic programming. Leave it empty
        return:
        	int output.
        complexity:
        	time: O(n)
            memory: O(n)
  	"""