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day 04

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This commit is contained in:
Spectre 2023-12-08 15:25:49 +01:00
parent cc82236995
commit e043e812dd
3 changed files with 268 additions and 4 deletions
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49
aoc2023/src/day04.rs
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@ -1,13 +1,58 @@
use std::collections::HashSet;
use shared::{Solution, Answer};
pub struct Day04;
impl Solution for Day04 {
fn part_1(&self, input: &str) -> Answer {
Answer::Unimplemented
let lines: Vec<&str> = input.split("\n").collect();
let cards = lines.iter()
.map(|l| l.split_once(": ").
unwrap()
.1
.split_once(" | ")
.unwrap())
.map(|(a, b)| (
a.split_whitespace().map(|y| y.parse::<u64>().unwrap()).collect::<HashSet<u64>>(),
b.split_whitespace().map(|y| y.parse::<u64>().unwrap()).collect::<HashSet<u64>>()
))
.collect::<Vec<(HashSet<u64>, HashSet<u64>)>>();
let mut out: u64 = 0;
for (card, winners) in cards {
let winning_nums = card.intersection(&winners).count();
if winning_nums > 0 {
out += 2u64.pow(winning_nums as u32 - 1)
}
}
Answer::from(out)
}
fn part_2(&self, input: &str) -> Answer {
Answer::Unimplemented
let lines: Vec<&str> = input.split("\n").collect();
let cards = lines.iter()
.map(|l| l.split_once(": ").
unwrap()
.1
.split_once(" | ")
.unwrap())
.map(|(a, b)| (
a.split_whitespace().map(|y| y.parse::<u64>().unwrap()).collect::<HashSet<u64>>(),
b.split_whitespace().map(|y| y.parse::<u64>().unwrap()).collect::<HashSet<u64>>()
))
.collect::<Vec<(HashSet<u64>, HashSet<u64>)>>();
let mut nums = vec![1u64; lines.len()];
for (i, (card, winners)) in cards.iter().enumerate() {
let winning_nums = card.intersection(&winners).count();
for j in (i+1)..(i+winning_nums+1) {
nums[j] += nums[i]
}
}
Answer::from(nums.iter().sum::<u64>())
}
}