fibonacci
# Easy fibonacci exercise
# Method #1
def fibonacci(n):
# 1th: 0
# 2th: 1
# 3th: 1 ...
if n == 1:
return 0
elif n == 2:
return 1
else:
return fibonacci(n - 1) + fibonacci(n - 2)
# Method #2
def fibonacci2(n):
if n == 0: return 0
n1 = 1
n2 = 1
# (1, n - 2) because start by 1, 2, 3... not 0, 1, 1, 2, 3....
for i in range(1, n - 2):
n1 += n2
n2 = n1 - n2
return n1
print(fibonacci(13))
# return the nth element in the fibonacci sequence