From e37a5af3a9de37537025b11bd9fd54487459edff Mon Sep 17 00:00:00 2001 From: June McEnroe Date: Fri, 1 Dec 2017 00:46:17 -0500 Subject: Day 1 --- 2017/src/bin/day01.rs | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 2017/src/bin/day01.rs (limited to '2017/src/bin/day01.rs') diff --git a/2017/src/bin/day01.rs b/2017/src/bin/day01.rs new file mode 100644 index 0000000..ee81d15 --- /dev/null +++ b/2017/src/bin/day01.rs @@ -0,0 +1,31 @@ +use std::io::{self, Read}; + +fn solve(input: &str) -> u32 { + let mut sum = 0; + + let chars = input.chars(); + let nexts = input.chars().cycle().skip(1); + + for (a, b) in chars.zip(nexts) { + if a == b { + sum += a.to_digit(10).unwrap(); + } + } + + sum +} + +fn main() { + let mut input = String::new(); + io::stdin().read_to_string(&mut input).unwrap(); + + println!("Part 1: {}", solve(input.trim())); +} + +#[test] +fn part1() { + assert_eq!(3, solve("1122")); + assert_eq!(4, solve("1111")); + assert_eq!(0, solve("1234")); + assert_eq!(9, solve("91212129")); +} -- cgit 1.4.1