Use prime factor util in 12 and move divisors code into util

This commit is contained in:
Linus Miller 2018-03-29 12:05:17 +02:00
parent 40158db6a1
commit 39030caf40
2 changed files with 49 additions and 41 deletions

66
0012.py
View File

@ -1,50 +1,33 @@
# Highly divisible triangular number
# Problem 12
# The sequence of triangle numbers is generated by adding the natural numbers. So the 7th triangle number would be 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28. The first ten terms would be:
# 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...
# Let us list the factors of the first seven triangle numbers:
# 1: 1
# 3: 1,3
# 6: 1,2,3,6
# 10: 1,2,5,10
# 15: 1,3,5,15
# 21: 1,3,7,21
# 28: 1,2,4,7,14,28
# We can see that 28 is the first triangle number to have over five divisors.
# What is the value of the first triangle number to have over five hundred divisors?
from collections import Counter
from functools import reduce
import util
def find_prime_factors(n):
factors = []
i = 2
while i <= n / i:
if n % i == 0:
factors.append(i)
n = int(n / i)
else:
i += 1
factors.append(n)
return factors
def find_divisers(num):
def recurse(tuples, product = 1):
factor, count = tuples[0]
for i in range(0, count + 1):
if (i != 0):
product = product * factor
if (len(tuples) > 1):
recurse(tuples[1:], product)
else:
result.append(product)
factors = find_prime_factors(num)
recurse(list(Counter(factors).items()))
result.sort()
return result
target = 76576500
for i in range(1, 100000):
result = reduce(lambda x,y: x + y, list(range(1, i + 1)))
# divisers = find_divisers(result)
factors = find_prime_factors(result)
factors = util.find_prime_factors(result)
total_count = 1
@ -52,7 +35,8 @@ for i in range(1, 100000):
total_count *= count + 1
if (total_count >= 500):
print(i)
# print(i)
# print(total_count)
print(result)
print(total_count)
print(result == target)
break

24
util.py
View File

@ -1,5 +1,29 @@
from collections import Counter
from functools import reduce
def divisors(num):
result = []
def recurse(tuples, product = 1):
factor, count = tuples[0]
for i in range(0, count + 1):
if (i != 0):
product = product * factor
if (len(tuples) > 1):
recurse(tuples[1:], product)
else:
result.append(product)
factors = find_prime_factors(num)
recurse(list(Counter(factors).items()))
result.sort()
return result
def find_largest_prime_factor(n):
prime_factor = 1
factors.append(prime_factor)