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ProjectEulerPython/Problem23.py

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Python

#ProjectEuler/Python/Problem23.py
#Matthew Ellison
# Created: 03-22-19
#Modified: 03-28-19
#Find the sum of all the positive integers which cannot be written as the sum of two abundant numbers
#All of my imports can be gotten from my pyClasses repository at https://bitbucket.org/Mattrixwv/pyClasses
"""
Copyright (C) 2019 Matthew Ellison
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
"""
from Stopwatch import Stopwatch
import Algorithms
__maxNum = 28123
#A function that returns true if num can be created by adding two elements from abund and false if it cannot
def isSum(abund: list, num: int) -> bool:
sumOfNums = 0
#Pick a number for the first part of the sum
for firstNum in range(0, len(abund)):
#Pick a number for the second part of the sum
for secondNum in range(0, len(abund)):
sumOfNums = abund[firstNum] + abund[secondNum]
if(sumOfNums == num):
return True
elif(sumOfNums > num):
break
#If you have run through the entire list and did not find a sum then it is false
return False
def Problem23():
#Setup the variables
divisorSums = []
#Make sure every element has a 0 in it's location
for cnt in range(0, __maxNum):
divisorSums.append(0)
#Get the sum of the divisors of all numbers < __maxNum
for cnt in range(1, __maxNum):
div = Algorithms.getDivisors(cnt)
if(len(div) > 1):
div.remove(div[len(div) - 1])
divisorSums[cnt] = sum(div)
#Get the abundant numbers
abund = []
for cnt in range(0, len(divisorSums)):
if(divisorSums[cnt] > cnt):
abund.append(cnt)
#Check if each number can be the sum of 2 abundant numbers and add to the sum if no
sumOfNums = 0
for cnt in range(1, __maxNum):
if(not isSum(abund, cnt)):
sumOfNums += cnt
#Print the results
print("The answer is " + str(sumOfNums))
if __name__ == "__main__":
timer = Stopwatch()
timer.start()
Problem23()
timer.stop()
print("It took " + timer.getString() + " to run this algorithm")
""" Results:
The answer is 4179871
It took 27.738 minutes to run this algorithm
"""