# import ...


# -----------------------------------------------------------------------------
# Exercise (Easy): Quick and Efficient Fibonacci

# This problem is fairly easy by itself, so an
# additional requirement is to run the function
# in O(n) time and O(1) space complexity.

# Ex) Input: 3   Output: 2
# -----------------------------------------------------------------------------
def fibonacci(n = 0):
    return 0


# -----------------------------------------------------------------------------
# Exercise (Easy): Palindrome

# Test if the input string is a palindrome.
# Only characters should be considered.

# Ex) Input: "5car3"   Output: True
# -----------------------------------------------------------------------------
def is_palindrome(word = ""):
    return False


# -----------------------------------------------------------------------------
# Exercise (Easy): Bit Flip

# Swap all even bits with odd bits in a number.

# Ex) Input: 23 (0 0 0 1 0 1 1 1)   Output: 43 (0 0 1 0 1 0 1 1)
# Explanation) The first two (1 1) bits swap, the next two (0 1) swap, then ...
# -----------------------------------------------------------------------------
def odd_even_bit_swap(n=0):
    # base_10 number(int) to base_2 number(string): bin(n)
    # base_2 number(string) to base_10 number(int): int(string, 2)
    return 0
