From 467181d7b73b9747d8ea88041187c06d12cc0adf Mon Sep 17 00:00:00 2001 From: Santo Cariotti Date: Tue, 7 Dec 2021 22:31:33 +0100 Subject: Add day3 --- day3/src/main.rs | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 day3/src/main.rs (limited to 'day3/src') diff --git a/day3/src/main.rs b/day3/src/main.rs new file mode 100644 index 0000000..aa7eda7 --- /dev/null +++ b/day3/src/main.rs @@ -0,0 +1,36 @@ +use std::fs::File; +use std::io::prelude::*; +use std::io::BufReader; + +fn main() -> Result<(), std::io::Error> { + let file = File::open("input.txt")?; + let reader = BufReader::new(&file); + + let lines: Vec<_> = reader.lines().map(|x| x.unwrap()).collect::>(); + let mut bits: Vec = vec![0; lines[0].len()]; + let half: u32 = (lines.len() / 2) as u32; + let mut gamma_string = String::new(); + let mut epsilon_string = String::new(); + + for line in lines { + for (index, char) in line.chars().enumerate() { + bits[index] += char.to_digit(10).unwrap(); + } + } + + for bit in bits { + if bit >= half { + gamma_string.push('1'); + epsilon_string.push('0'); + } else { + gamma_string.push('0'); + epsilon_string.push('1'); + } + } + let gamma_rate = isize::from_str_radix(&gamma_string, 2).unwrap(); + let epsilon_rate = isize::from_str_radix(&epsilon_string, 2).unwrap(); + + println!("{}", gamma_rate * epsilon_rate); + + Ok(()) +} -- cgit v1.2.3-18-g5258