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authorSanto Cariotti <santo@dcariotti.me>2022-12-05 19:46:06 +0100
committerSanto Cariotti <santo@dcariotti.me>2022-12-05 19:46:06 +0100
commitcf6303a5bc1558ebdb7b467da38f74cd3ac3a9b1 (patch)
tree6292cb239a8cf114179c6e7c8b3015840dfbae6e /2021/day4/src
parent6e10cc2773fcaff64902b13f44443da014f38be7 (diff)
Add 2022
Diffstat (limited to '2021/day4/src')
-rw-r--r--2021/day4/src/main.rs107
1 files changed, 107 insertions, 0 deletions
diff --git a/2021/day4/src/main.rs b/2021/day4/src/main.rs
new file mode 100644
index 0000000..4b2f9b3
--- /dev/null
+++ b/2021/day4/src/main.rs
@@ -0,0 +1,107 @@
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+
+fn part1(grids: &Vec<Vec<u32>>, mut inputs: Vec<u32>) -> u32 {
+ let mut values = Vec::<u32>::new();
+
+ for _ in 0..4 {
+ values.push(inputs.remove(0));
+ }
+
+ let mut winner: i8 = -1;
+ for input in inputs {
+ if winner >= 0 {
+ break;
+ }
+ values.push(input);
+ for i in 0..grids.len() {
+ // Search by rows
+ for j in [0, 5, 10, 15, 20] {
+ let mut n = 0;
+ for k in 0..5 {
+ let x = grids[i][j + k];
+ if values.iter().any(|&i| i == x) {
+ n += 1;
+ }
+ }
+ if n == 5 {
+ winner = i as i8;
+ }
+ }
+
+ // Search by cols
+ if winner < 0 {
+ for j in 0..5 {
+ let mut n = 0;
+ for k in [0, 5, 10, 15, 20] {
+ let x = grids[i][j + k];
+ if values.iter().any(|&i| i == x) {
+ n += 1;
+ }
+ }
+ if n == 5 {
+ winner = i as i8;
+ }
+ }
+ }
+
+ if winner >= 0 {
+ break;
+ }
+ }
+ }
+
+ let mut sum = 0;
+ for x in &grids[winner as usize] {
+ if values.iter().any(|&i| i == *x) {
+ continue;
+ }
+
+ sum += x;
+ }
+
+ sum * values.pop().unwrap()
+}
+
+fn main() -> std::io::Result<()> {
+ let file = File::open("input.txt")?;
+ let reader = BufReader::new(file);
+ let mut lines = reader.lines();
+
+ let inputs: Vec<_> = lines
+ .next()
+ .unwrap()
+ .unwrap()
+ .trim()
+ .split(',')
+ .map(|x| x.parse::<u32>().unwrap())
+ .collect::<Vec<u32>>();
+
+ let mut grids: Vec<Vec<u32>> = vec![];
+ let mut n: usize = 0;
+
+ lines.next(); // Ignore the first empty line
+ while let Some(line) = lines.next() {
+ let mut line = line.unwrap();
+ grids.push(Vec::with_capacity(5 * 5));
+
+ for _ in 0..5 {
+ grids[n].extend(
+ line.trim()
+ .split(' ')
+ .filter(|x| !x.is_empty())
+ .map(|x| x.parse::<u32>().unwrap())
+ .collect::<Vec<u32>>(),
+ );
+ line = match lines.next() {
+ Some(x) => x.unwrap(),
+ None => "".to_string(),
+ };
+ }
+ n += 1;
+ }
+
+ println!("{}", part1(&grids, inputs.clone()));
+
+ Ok(())
+}