92 lines
2 KiB
Rust
92 lines
2 KiB
Rust
pub const INPUT: &str = include_str!("./input.txt");
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fn parse_input(input: &'static str) -> Vec<[u32; 2]> {
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let input = input
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.lines()
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.map(|line| -> [u32; 2] {
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let nums = line
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.split_whitespace()
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.map(|num| num.parse::<u32>().unwrap())
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.collect::<Vec<_>>();
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[nums[0], nums[1]]
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})
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.collect::<Vec<_>>();
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input
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}
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pub fn main() {
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let input = parse_input(INPUT);
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let result_1 = part_1(&input);
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println!("{result_1}");
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let result_2 = part_2(&input);
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println!("{result_2}");
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}
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fn part_1(input: &Vec<[u32; 2]>) -> u32 {
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let mut left = vec![];
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let mut right = vec![];
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for pair in input {
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left.push(pair[0]);
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right.push(pair[1]);
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}
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left.sort_unstable();
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right.sort_unstable();
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let mut diff = 0;
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for i in 0..left.len() {
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diff += u32::abs_diff(left[i], right[i]);
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}
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diff
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}
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fn part_2(input: &Vec<[u32; 2]>) -> u32 {
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let mut left = vec![];
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let mut right = vec![];
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for pair in input {
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left.push(pair[0]);
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right.push(pair[1]);
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}
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let mut result = 0;
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for num in left {
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result += num * right.iter().filter(|&&x| x == num).count() as u32;
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}
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result
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}
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#[cfg(test)]
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mod tests {
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use crate::parse_input;
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const SAMPLE_INPUT: &str = r#"3 4
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4 3
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2 5
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1 3
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3 9
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3 3"#;
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#[test]
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fn test_part_1_with_sample_solution() {
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let input = parse_input(SAMPLE_INPUT);
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assert_eq!(super::part_1(&input), 11)
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}
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#[test]
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fn test_part_1_with_solution() {
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let input = parse_input(super::INPUT);
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assert_eq!(super::part_1(&input), 2192892);
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}
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#[test]
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fn test_part_2_with_sample_solution() {
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let input = parse_input(SAMPLE_INPUT);
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assert_eq!(super::part_2(&input), 31)
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}
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#[test]
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fn test_part_2_with_solution() {
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let input = parse_input(super::INPUT);
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assert_eq!(super::part_2(&input), 22962826);
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}
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}
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