def main():
lst0 = list(1, 3, list(5, 7), 9)
print_list(lst0)
seven0 = car(
cdr(
car(
cdr(
cdr(lst0)))))
lst1 = list(list(7))
print_list(lst1)
seven1 = car(car(lst1))
lst2 = list(1, list(2, list(3, list(4, list(5, list(6, 7))))))
print_list(lst2)
seven2 = car(cdr(
car(cdr(
car(cdr(
car(cdr(
car(cdr(
car(cdr(lst2))))))))))))
assert 7 == seven0
assert 7 == seven1
assert 7 == seven2
def is_pair(lst):
if utility.is_list(lst):
car_lst = utility.car(lst)
cdr_lst = utility.cdr(lst)
if (not utility.is_list(car_lst)) and (not utility.is_list(cdr_lst)):
return True
return False
def square_list(list):
if utility.is_null(list):
return utility.list()
else:
return utility.cons(
square(utility.car(list)),
square_list(utility.cdr(list)))
def last_pair(lst):
if utility.is_null(lst):
raise ValueError('empty list')
if utility.is_null(utility.cdr(lst)):
return utility.car(lst)
else:
return last_pair(utility.cdr(lst))
def reverse(lst):
if utility.is_null(lst):
return None
elif utility.length(lst) == 1:
return lst
else:
x = utility.car(lst)
xs = utility.cdr(lst)
return utility.append(reverse(xs), utility.list(x))
def same_parity_iter(a):
"""
:type a: FunctionType | object
:return:
"""
if is_null(a):
return None
else:
b = car(a) # type: int
if is_even(x - b):
return cons(b, same_parity_iter(cdr(a)))
else:
return same_parity_iter(cdr(a))
def deep_reverse(lst):
def deep_reverse_element(a):
if callable(a):
return utility.list(deep_reverse(a))
else:
return utility.list(a)
def deep_reverse_of_length_one(lst):
return deep_reverse_element(utility.car(lst))
# utility.print_list(lst)
if utility.is_null(lst):
return None
elif utility.length(lst) == 1:
return deep_reverse_of_length_one(lst)
else:
x = utility.car(lst)
xs = utility.cdr(lst)
x_rev = deep_reverse_element(x)
xs_rev = deep_reverse(xs)
return utility.append(xs_rev, x_rev)
def x_point(p):
return utility.car(p)
def test_sub_interval(self):
result = sub_interval(self.interval0, self.interval1)
self.assertEqual(-14, utility.car(result))
self.assertEqual(3, utility.cdr(result))
def for_each(f, lst):
if not utility.is_null(lst):
f(utility.car(lst))
for_each(f, utility.cdr(lst))
def deep_reverse_of_length_one(lst):
return deep_reverse_element(utility.car(lst))
def left_branch(mobile):
return utility.car(mobile)
def iter(things, answer):
if is_null(things):
return answer
else:
iter(cdr(things), cons(answer, square(car(things))))
def subsets(l):
if is_null(l):
return list(list())
rest = subsets(cdr(l))
return append(rest, map(lambda x: cons(car(l), x) , rest))
def width_rectangle(r):
return utility.car(r)
def branch_structure(branch):
return utility.car(utility.cdr(branch))
def branch_length(branch):
return utility.car(branch)
def right_branch(mobile):
return utility.car(utility.cdr(mobile))
def start_segment(s):
return utility.car(s)
def accumulate(op, initial, list):
if is_null(list):
return initial
else:
return op(car(list), accumulate(op, initial, cdr(list)))
def start_rectangle(r):
return utility.car(r)
def numer(x):
return utility.car(x)
def lower_bound(x):
return utility.car(x)
def first_denomination(coin_values):
return utility.car(coin_values)