I need help to create a recursive function that finds and adds the even elements of a tuple, I would greatly appreciate the help.
def conta_pares(t):
'''conta_pares : tuplo -> inteiro
recebe tuplo de inteiros e devolve o numero de elementos pares no tuplo'''
if t == ():
return 0
else:
#t = (t[1:])
#if a % 2 == 0:
return t[0] + conta_pares(t[1:])
Just check if the value is even by checking the rest of the division by 2. If it is zero it is even; if 1 is odd. When even, you must add 1 plus the number of even numbers in the remainder of the tuple; if it is odd, it should return only the number of even numbers in the rest of the tuple.
def pares(t):
if not t:
return 0
par = (t[0] % 2 == 0)
if par:
return 1 + pares(t[1:])
else:
return pares(t[1:])
Or, in a simplified form:
return (1 if par else 0) + pares(t[1:])
If you consider that the Boolean type in Python is an integer-type specialization, being False equal to zero and True equal to 1, you could just do:
def pares(t):
if not t:
return 0
return (t[0] % 2 == 0) + pares(t[1:]