59 lines
2.1 KiB
Rust
59 lines
2.1 KiB
Rust
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#![feature(vec_push_within_capacity)]
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use std::collections::VecDeque;
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use itertools::Itertools;
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const INPUT: &str = include_str!("input.txt");
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// I manually transpiled my program input to rust code, and then removed everything after the first print
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// I hope this doesn't count as including my input, please have mercy o lord Eric Wastl
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fn calculate(value: u64) -> u64 {
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let mut register = (value, 0, 0);
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register.1 = register.0 & 0b111; // Take the lowest 3 bits
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register.1 ^= 0b010; // XOR Depends on lowest 3 bits
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register.2 = register.0 / 2u64.pow(register.1.try_into().unwrap()); // Remove some bits of A depending on its last 3
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register.1 ^= 0b011; // XOR Depends on lowest 3 bits
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register.1 ^= register.2; // XOR Depends on lowest 3 and full
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return register.1 & 0b111;
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}
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fn main() {
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// Input parsing
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let (_, instructions) = INPUT.split_once("\n\n").unwrap();
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let instructions = instructions[9..]
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.trim_ascii_end()
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.split(",")
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.into_iter()
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.map(|num| {
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num.parse::<u64>().unwrap()
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})
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.collect_vec();
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// Since the program operates in chunks of 3
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// And since each chunk relies on the chunks above it
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// If we start from the last digit then we can get that right, and work from there
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// We have to use a queue/stack, because multiple inputs can get a correct digit, so we have to support branching
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let mut branches = VecDeque::<(u64, usize)>::with_capacity(instructions.len() * 3);
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branches.push_back((0b000, 0));
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let mut results = Vec::<u64>::new();
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loop {
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let Some((next, digits_calculated)) = branches.pop_back() else {
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break;
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};
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for i in 0b000..=0b111u64 {
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if calculate(next | i) == instructions[15 - digits_calculated] {
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if digits_calculated == 15 {
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results.push(next | i);
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} else {
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branches.push_back(((next | i) << 3, digits_calculated + 1));
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}
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}
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}
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}
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println!("Result: {}", results.iter().min().unwrap());
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}
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