68 lines
1.2 KiB
Rust
68 lines
1.2 KiB
Rust
#[derive(Debug)]
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struct MaxValues {
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pub a: isize,
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pub b: isize,
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pub n: isize,
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}
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#[derive(Clone, Copy)]
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enum IsPrime {
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Prime,
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NotPrime,
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}
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impl IsPrime {
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pub fn is_prime(&self) -> bool {
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match self {
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Self::Prime => true,
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Self::NotPrime => false,
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}
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}
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}
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fn is_number_prime(i: isize, sieve: &Vec<IsPrime>) -> bool {
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if i < 0 {
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false
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}
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else {
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sieve[i as usize].is_prime()
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}
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}
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fn main() {
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let mut sieve = vec![IsPrime::Prime; 1_000_000];
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for i in 2..999_999_usize {
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if is_number_prime(i as isize, &sieve) {
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let mut i_m = i * 2;
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while i_m <= 999_999 {
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sieve[i_m] = IsPrime::NotPrime;
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i_m += i;
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}
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}
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}
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let mut maxes = MaxValues { a: 0, b: 0, n: 0 };
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for a in -999..999 {
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for b in -1000..1000 {
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let mut n: isize = 0;
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while is_number_prime(n.pow(2) + a*n + b, &sieve) {
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n += 1;
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}
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if n > maxes.n {
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maxes.n = n;
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maxes.a = a;
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maxes.b = b;
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}
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}
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}
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println!("{:?}", maxes);
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}
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