#ProjectEuler/Python/Problem27.py #Matthew Ellison # Created: 09-15-19 #Modified: 07-24-21 #Find the product of the coefficients, |a| < 1000 and |b| <= 1000, for the quadratic expression that produces the maximum number of primes for consecutive values of n, starting with n=0. #Unless otherwise listed, all of my non-standard imports can be gotten from my pyClasses repository at https://bitbucket.org/Mattrixwv/pyClasses """ Copyright (C) 2020 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 . """ from Problems.Problem import Problem import NumberAlgorithms class Problem27(Problem): #Functions #Constructor def __init__(self) -> None: super().__init__("Find the product of the coefficients, |a| < 1000 and |b| <= 1000, for the quadratic expression that produces the maximum number of primes for consecutive values of n, starting with n=0") self.topA = 0 #The A for the most n's generated self.topB = 0 #The B for the most n's generated self.topN = 0 #The most n's generated self.primes = [] #A list of all primes that could possibly be generated with this formula #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 primes primes = NumberAlgorithms.getPrimes(12000) #A list of all primes that could possibly be generated with this formula #Start with the lowest possible A and check all possibilities after that for a in range(-999, 999): #Start with the lowest possible B and check all possibilities after that for b in range(-1000, 1000): #Start with n=0 and check the formula to see how many primes you can get get with concecutive n's n = 0 quadratic = (n * n) + (a * n) + b while(quadratic in primes): n += 1 quadratic = (n * n) + (a * n) + b n -= 1 #Negate an n because the last formula failed #Set all the largest numbers if this created more primes than any other if(n > self.topN): self.topN = n self.topB = b self.topA = a #Stop the timer self.timer.stop() #Save the results self.result = "The greatest number of primes found is " + str(self.topN) self.result += "\nIt was found with A = " + str(self.topA) + ", B = " + str(self.topB) self.result += "\nThe product of A and B is " + str(self.topA * self.topB) #Throw a flag to show the problem is solved self.solved = True #Reset the problem so it can be run again def reset(self) -> None: super().reset() self.topA = 0 self.topB = 0 self.topN = 0 self.primes.clear() #Gets #Returns the result of solving the problem def getResult(self) -> str: self.solvedCheck("result") return f"The greatest number of primes found is {self.topN}\n" \ f"It was found with A = {self.topA}, B = {self.topB}\n" \ f"The product of A and B is {self.topA * self.topB}" #Returns the top A that was generated def getTopA(self) -> int: self.solvedCheck("largest A") return self.topA #Returns the top B that was generated def getTopB(self) -> int: self.solvedCheck("largest B") return self.topA #Returns the top N that was generated def getTopN(self) -> int: self.solvedCheck("largest N") return self.topA #Returns the product of A and B for the answer def getProduct(self) -> int: self.solvedCheck("product of A and B") return self.topA * self.topB """ Results: The greatest number of primes found is 70 It was found with A = -61, B = 971 The product of A and B is -59231 It took an average of 49.963 seconds to run this problem through 100 iterations """