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-rw-r--r--day4/src/main.rs103
1 files changed, 103 insertions, 0 deletions
diff --git a/day4/src/main.rs b/day4/src/main.rs
new file mode 100644
index 0000000..aed66ec
--- /dev/null
+++ b/day4/src/main.rs
@@ -0,0 +1,103 @@
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+
+fn main() -> std::io::Result<()> {
+ let file = File::open("input.txt")?;
+ let reader = BufReader::new(file);
+ let mut lines = reader.lines();
+
+ let mut 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;
+ }
+
+ 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;
+ }
+
+ println!("{}", sum * values.pop().unwrap());
+
+ Ok(())
+}