76 lines
2.0 KiB
Rust
76 lines
2.0 KiB
Rust
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use crate::common::AdventOfCodeDay;
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pub struct Day25 {
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pkey_card: u64,
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pkey_door: u64,
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}
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impl Day25 {
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pub fn new() -> Self {
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let input_bytes = include_bytes!("../res/25_input.txt");
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let input_str = String::from_utf8_lossy(input_bytes);
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let lines = input_str
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.lines()
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.map(|p| String::from(p))
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.map(|p| p.parse::<u64>().unwrap())
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.collect::<Vec<_>>();
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Self {
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pkey_card: lines[0],
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pkey_door: lines[1],
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}
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}
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}
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impl Day25 {
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fn transform(subjectnumber: u64, loopcount: usize) -> u64 {
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let mut v = 1;
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for _ in 0..loopcount {
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v *= subjectnumber;
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v %= 20201227;
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}
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return v;
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}
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fn transform_back(subjectnumber: u64, pkey_dest: u64) -> usize {
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let mut v = 1;
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for lc in 1.. {
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v *= subjectnumber;
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v %= 20201227;
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if v == pkey_dest {
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return lc;
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}
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}
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panic!();
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}
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}
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impl AdventOfCodeDay for Day25 {
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fn task_1(&self) -> String {
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verboseln!("card public key: {}", self.pkey_card);
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verboseln!("door public key: {}", self.pkey_door);
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verboseln!();
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let loopsize_card = Self::transform_back(7, self.pkey_card);
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verboseln!("card loop size: {}", loopsize_card);
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let loopsize_door = Self::transform_back(7, self.pkey_door);
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verboseln!("door loop size: {}", loopsize_door);
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verboseln!();
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let skey_card = Self::transform(self.pkey_card, loopsize_door);
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verboseln!("card encryption key: {}", skey_card);
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let skey_door = Self::transform(self.pkey_door, loopsize_card);
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verboseln!("door encryption key: {}", skey_door);
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verboseln!();
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return skey_card.to_string().to_owned();
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}
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fn task_2(&self) -> String {
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return "".to_owned()
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}
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}
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