Created
December 16, 2020 00:29
-
-
Save dcbriccetti/2e1b58c28a6d3d780805287905a2d055 to your computer and use it in GitHub Desktop.
Advent of Code 2020 Day 14 Part 1 Solution in Rust
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| use std::collections::HashMap; | |
| use regex::Regex; | |
| use std::fs::File; | |
| use std::io::{BufRead, BufReader}; | |
| fn main() { | |
| let mut memory: HashMap<u64, u64> = HashMap::new(); | |
| let mut or_mask: u64 = 0; | |
| let mut and_mask: u64 = 0; | |
| let rx_mask = Regex::new(r"mask = ([X10]{36})").unwrap(); | |
| let rx_mem = Regex::new(r"mem\[(\d+)\] = (\d+)").unwrap(); | |
| let file = File::open("test_data.txt").unwrap(); | |
| for result in BufReader::new(file).lines() { | |
| let line = result.unwrap(); | |
| for captures in rx_mask.captures(&line) { | |
| let mask_string = &captures[1]; | |
| let mut two_power = 36; | |
| let mut off_bits: u64 = 0; | |
| let mut on_bits: u64 = 0; | |
| for mask_char in mask_string.chars() { | |
| two_power -= 1; | |
| let bit_position: u64 = 1 << two_power; | |
| if mask_char == '0' { | |
| off_bits |= bit_position | |
| } | |
| if mask_char == '1' { | |
| on_bits |= bit_position | |
| } | |
| } | |
| or_mask = on_bits; | |
| and_mask = !off_bits; | |
| println!("{} {:b} {:b}", mask_string, or_mask, and_mask); | |
| } | |
| for captures in rx_mem.captures(&line) { | |
| let addr: u64 = captures[1].parse().unwrap(); | |
| let unmasked_val: u64 = captures[2].parse().unwrap(); | |
| let masked_val: u64 = { | |
| let bits_off_val: u64 = unmasked_val & and_mask; | |
| let bits_on_val: u64 = bits_off_val | or_mask; | |
| println!("{} <- val: {}, off: {}, on: {}", addr, unmasked_val, bits_off_val, bits_on_val); | |
| bits_on_val | |
| }; | |
| memory.insert(addr, masked_val); | |
| } | |
| } | |
| println!("Memory: {:?}", memory); | |
| let sum = memory.values().fold(0, |acc, v| acc + v); | |
| println!("Sum of all values: {}", sum) | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment