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100 lines
3.5 KiB
Python
100 lines
3.5 KiB
Python
#ProjectEuler/Python/Problem4.py
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#Matthew Ellison
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# Created: 01-28-19
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#Modified: 10-30-20
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#Find the largest palindrome made from the product of two 3-digit numbers
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#Unless otherwise listed, all of my non-standard imports can be gotten from my pyClasses repository at https://bitbucket.org/Mattrixwv/pyClasses
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"""
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Copyright (C) 2020 Matthew Ellison
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>.
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"""
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from Problems.Problem import Problem
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from Unsolved import Unsolved
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class Problem4(Problem):
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#Variables
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__lowestNum = 100
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__highestNum = 1000
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#Functions
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#Constructor
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def __init__(self):
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super().__init__("Find the largest palindrome made from the product of two 3-digit numbers")
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self.palindromes = [] #Holds all of the palindromes
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#Operational functions
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#Solve the problem
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def solve(self):
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#If the problem has already been solved do nothing and end the function
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if(self.solved):
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return
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#Start the timer
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self.timer.start()
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#Loop through every number from __lowestNum to __highestNum twice and multiply every number together
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for firstNum in range(self.__lowestNum, self.__highestNum + 1):
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for secondNum in range(firstNum, self.__highestNum + 1): #You can start at num1 because 100 * 101 == 101 * 100
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#Get the product
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currentNum = firstNum * secondNum
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#If the number is a palindrome add it to the list of palindromes, otherwise ignore it
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#Using strings makes it easier to determine a palindrome
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if(str(currentNum) == str(currentNum)[::-1]):
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self.palindromes.append(currentNum)
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#If it's not a palindrom ignore it
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#Sort the palindromes so that the last element is the largest
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self.palindromes.sort()
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#Stop the timer
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self.timer.stop()
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#Throw a flag to show the problem is solved
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self.solved = True
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#Reset the problem so it can be run again
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def reset(self):
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super().reset()
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self.palindromes.clear()
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#Gets
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#Returns the result of solving the problem
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def getResult(self):
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#If the problem hasn't been solved throw an exception
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if(not self.solved):
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raise Unsolved("You must solve the problem before you can see the result")
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return f"The largest palindrome made from the product of two 3-digit numbers is {self.palindromes[len(self.palindromes) - 1]}"
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#Returns the list of all palindromes
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def getPalindromes(self) -> list:
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#If the problem hasn't been solved throw an exceptions
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if(not self.solved):
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raise Unsolved("You must solve the problem before you can get the list of palindromes")
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return self.palindromes
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#Returns the largest palindrome
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def getLargestPalindrome(self) -> int:
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#If the problem hasn't been solved throw an exceptions
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if(not self.solved):
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raise Unsolved("You must solve the problem before you can get the largest palindrome")
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return self.palindromes[len(self.palindromes) - 1]
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"""Results:
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The largest palindrome made from the product of two 3-digit numbers is 906609
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It took an average of 149.187 milliseconds to run this problem through 100 iterations
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"""
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