def main():
"""Perform gradient descent using user-provided parameters.
This asks the user to provide a learning rate, an initial starting value,
and a maximum step count to avoid infinite iteration.
"""
learning_rate = get_float_input('Input a learning rate, a=')
initial_x = get_float_input('Input an initial value, x0=')
step_count = get_int_input('Input the number of steps:')
print('Now descending...')
descend(initial_x=initial_x, step_count=step_count, step_size=learning_rate,
callback=print_update)
def parse_input(file_name):
return common.get_int_input(file_name)
def solve_2(numbers, target_sum):
half = target_sum / 2
entry1 = next(
(n for n in numbers if (target_sum - n) in numbers and n != half),
None)
entry2 = (target_sum - entry1) if entry1 is not None else None
return entry1, entry2
def solve_3(numbers, target_sum):
all_numbers = numbers
numbers = numbers.copy()
for entry1 in all_numbers:
numbers.remove(entry1)
entry2, entry3 = solve_2(numbers, target_sum - entry1)
if None not in (entry2, entry3):
return entry1, entry2, entry3
numbers.add(entry1)
return None, None, None
file_name = '01.txt'
target_sum = 2020
number_list = common.get_int_input(file_name)
numbers = set(number_list)
if len(number_list) > len(numbers):
raise Exception("Current implementation can not handle duplicates")
entry1, entry2, entry3 = solve_3(numbers, target_sum)
product = entry1 * entry2 * entry3
print(product)