Project Euler/27

Problem Statement

Euler discovered a quadratic formula that would generate primes:

$n^{2}+n+41$

for $0\leq n\leq 39$

Another formula, $n^{2}-79n+1601$, was discovered, that produces 80 primes for consecutive values $0\leq n\leq 79$

Now consider equadratics of the form

$n^{2}+an+b$

where $|a|\leq 1000$, $|b|\leq 1000$

Find product of coefficients a, b for the quadratic expression producing the maximum number of primes for consecutive values of n, starting with n = 0

Solution

Solution: https://git.charlesreid1.com/cs/euler/src/branch/master/java/Problem027.java

Implemented 2 nested for loops to search for parameter values by brute force. Keep running track of consecutive number of primes generated, and best a/b. Return them at the end.

This algorithm did not have any trickness, or require any special optimization. Used a standard prime number sieve, nothing special.