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| 1 | +use crate::common::{InputType, read_input, Range}; |
| 2 | +use std::cmp::{max, min}; |
| 3 | +use std::collections::HashSet; |
| 4 | + |
| 5 | +const DAY: usize = 5; |
| 6 | + |
| 7 | +fn parse(input_type: &InputType) -> (Vec<Range>, Vec<i64>) { |
| 8 | + let input = read_input(DAY, input_type); |
| 9 | + let (ranges, ingredients) = input.split_once("\n\n").unwrap(); |
| 10 | + |
| 11 | + let ranges: Vec<_> = ranges |
| 12 | + .lines() |
| 13 | + .map(|line: &str| { |
| 14 | + let (l, h) = line.split_once("-").unwrap(); |
| 15 | + Range { |
| 16 | + l: l.parse::<i64>().unwrap(), |
| 17 | + h: h.parse::<i64>().unwrap(), |
| 18 | + } |
| 19 | + }) |
| 20 | + .collect(); |
| 21 | + |
| 22 | + let ingredients: Vec<_> = ingredients |
| 23 | + .lines() |
| 24 | + .map(|line: &str| line.parse::<i64>().unwrap()) |
| 25 | + .collect(); |
| 26 | + |
| 27 | + (ranges, ingredients) |
| 28 | +} |
| 29 | + |
| 30 | +pub fn part_one(input_type: &InputType) { |
| 31 | + let (ranges, ingredients) = parse(input_type); |
| 32 | + |
| 33 | + let mut sum = 0; |
| 34 | + for ingredient in ingredients { |
| 35 | + for range in &ranges { |
| 36 | + if range.l <= ingredient && range.h >= ingredient { |
| 37 | + sum += 1; |
| 38 | + break; |
| 39 | + } |
| 40 | + } |
| 41 | + } |
| 42 | + println!("{}", sum); |
| 43 | +} |
| 44 | + |
| 45 | +pub fn part_two(input_type: &InputType) { |
| 46 | + let (ranges, _) = parse(input_type); |
| 47 | + |
| 48 | + let mut range_list = Vec::new(); |
| 49 | + |
| 50 | + for range in ranges { |
| 51 | + if range_list.is_empty() { |
| 52 | + range_list.push(range); |
| 53 | + continue; |
| 54 | + } |
| 55 | + |
| 56 | + let mut intersecting: Vec<Range> = range_list |
| 57 | + .iter() |
| 58 | + .filter(|r| r.intersection(&range).is_some()) |
| 59 | + .map(|r| r.clone()) |
| 60 | + .collect(); |
| 61 | + intersecting.push(range.clone()); |
| 62 | + |
| 63 | + let l = intersecting.iter().map(|r| r.l).min().unwrap(); |
| 64 | + let h = intersecting.iter().map(|r| r.h).max().unwrap(); |
| 65 | + let union = Range { l, h }; |
| 66 | + |
| 67 | + range_list.retain(|r| r.intersection(&range).is_none()); |
| 68 | + range_list.push(union); |
| 69 | + } |
| 70 | + |
| 71 | + let sum: i64 = range_list.iter().map(|r| r.len()).sum(); |
| 72 | + println!("{}", sum); |
| 73 | +} |
| 74 | + |
| 75 | +#[cfg(test)] |
| 76 | +mod test { |
| 77 | + use crate::day05::Range; |
| 78 | + |
| 79 | + #[test] |
| 80 | + fn test_range_intersect() { |
| 81 | + let r1 = Range { l: 3, h: 5 }; |
| 82 | + let r2 = Range { l: 6, h: 8 }; |
| 83 | + let r3 = Range { l: 4, h: 9 }; |
| 84 | + let r4 = Range { l: 1, h: 4 }; |
| 85 | + let r5 = Range { l: 5, h: 6 }; |
| 86 | + |
| 87 | + assert_eq!(0, r1.intersect(&r2)); |
| 88 | + assert_eq!(2, r1.intersect(&r3)); |
| 89 | + assert_eq!(2, r1.intersect(&r4)); |
| 90 | + assert_eq!(1, r1.intersect(&r5)); |
| 91 | + assert_eq!(3, r1.intersect(&r1)); |
| 92 | + } |
| 93 | +} |
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