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euler-project/problems/005_problem.py
2020-04-26 14:24:58 -04:00

134 lines
2.8 KiB
Python
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#!/usr/bin/env python
# Problem 5:
#
# 2520 is the smallest number that can
# be divided by each of the numbers
# from 1 to 10 without any remainder.
#
# What is the smallest positive number
# that is evenly divisible by all of the
# numbers from 1 to 20?
#
import decorators # Typically imported to compute execution duration of functions.
import time # Typically imported for sleep function, to slow down execution in terminal.
import typing
import pprint
import numpy
# Create function that finds the next
# prime number when supplied with an
# intitial integer.
def primes_gen(start_n: int,max_n: int):
"""
Returns a generator object, containing the
primes inside a specified range.
primes_gen(start_n,max_n)
param 'start_n': Previous prime.
param 'max_n': Maximum
"""
start_n += 1
for candidate in range(start_n,max_n):
notPrime = False
if candidate in [0,1,2,3]:
yield candidate
for dividend in range(2,candidate):
if candidate%dividend == 0:
notPrime = True
if not notPrime:
yield candidate
def find_prime_factors(n: int):
"""
Return a list object containing all
prime factors of the provided integer, n.
find_prime_factors(n)
param 'n': The integer to be analyzed.
"""
returned_prime = list(primes_gen(0,n))
pprint.pprint(returned_prime)
return returned_prime
def evenly_divisible(candidate: int,factors: list):
"""
Determines if the supplied integer candidate is
evenly divisble by the supplied list of factors.
evenly_divisible(candidate: int, factors: list)
param 'candidate': Integer to be tested.
param 'factors': List of factors for the modulus operator.
"""
modulus_sum = 0
for n in factors:
modulus_sum += candidate%n
if modulus_sum == 0:
return True
else:
return False
@decorators.function_timer
def main():
# Receive problem inputs...
smallest_factor = 1
largest_factor = 5
# Compute intermediate inputs
factor_list = [int(i) for i in range(smallest_factor,largest_factor+1)]
maximum_solution_bound = 1
for f in factor_list:
maximum_solution_bound *= f
common = []
product = 1
#
# Brute force method below breaks down
# and doesn't scale well ...
#
# # Initialize loop parameters
# n = 1
# test_passed = False
#
# while n<maximum_solution_bound and not test_passed:
# test_passed = evenly_divisible(n,factor_list)
# if not test_passed:
# n += 1
# Mathematically, the trick is to recognize
# that this a LCM (Least Common Multiple)
# problem. The solution is list all
# the prime factors of each number in
# the factor list, then compute their
# collective product.
pprint.pprint(common)
for j in common:
for k in j:
product *= k
print(product)
print(set(factor_list))
# print("The largest palindrome number which is a product of two numbers of length {} is {} ... ".format("foo_list","foo"))
main()