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ProjectEulerPython/Problems/Problem23.py

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#ProjectEuler/Python/Problem23.py
#Matthew Ellison
# Created: 03-22-19
#Modified: 07-24-21
#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) 2021 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 Problems.Problem import Problem
import NumberAlgorithms
class Problem23(Problem):
#Variables
__maxNum = 28123
#Functions
#Constructor
def __init__(self) -> None:
super().__init__("Find the sum of all the positive integers which cannot be written as the sum of two abundant numbers")
self.divisorSums = []
self.reserveArray()
self.sum = 0
#Operational functions
#Solve the problem
def solve(self) -> None:
#If the problem has already been solved do nothing and end the function
if(self.solved):
return
#Start the timer
self.timer.start()
#Get the sum of the divisors of all numbers < __maxNum
for cnt in range(1, self.__maxNum):
div = NumberAlgorithms.getDivisors(cnt)
if(len(div) > 1):
div.remove(div[len(div) - 1])
self.divisorSums[cnt] = sum(div)
#Get the abundant numbers
abund = []
for cnt in range(0, len(self.divisorSums)):
if(self.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
self.sum = 0
for cnt in range(1, self.__maxNum):
if(not self.isSum(abund, cnt)):
self.sum += cnt
#Stop the timer
self.timer.stop()
#Throw a flag to show the problem is solved
self.solved = True
#Reserve the size of the array to speed up insertion
def reserveArray(self) -> None:
#Make sure every element has a 0 in it's location
for _ in range(0, self.__maxNum):
self.divisorSums.append(0)
#A function that returns true if num can be created by adding two elements from abund and false if it cannot
def isSum(self, 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
#Reset the problem so it can be run again
def reset(self) -> None:
super().reset()
self.divisorSums.clear()
self.reserveArray()
self.sum = 0
#Gets
#Returns the result of solving the problem
def getResult(self) -> str:
self.solvedCheck("result")
return f"The answer is {self.sum}"
#Returns the sum of the numbers asked for
def getSum(self) -> int:
self.solvedCheck("sum")
return self.sum
""" Results:
The answer is 4179871
It took an average of 24.184 minutes to run this problem through 10 iterations
"""