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-rw-r--r--2018/src/day2.rs64
-rw-r--r--2018/src/main.rs19
2 files changed, 77 insertions, 6 deletions
diff --git a/2018/src/day2.rs b/2018/src/day2.rs
new file mode 100644
index 0000000..6564938
--- /dev/null
+++ b/2018/src/day2.rs
@@ -0,0 +1,64 @@
+use std::io;
+use std::io::BufRead;
+use std::collections::HashMap;
+
+fn close_enough(a: &str, b: &str) -> bool {
+ let mut num = 0;
+
+ for (ch1, ch2) in a.chars().zip(b.chars()) {
+ if ch1 != ch2 {
+ num += 1;
+ if num > 1 { return false; }
+ }
+ }
+
+ return num == 1;
+}
+
+pub fn main<T: BufRead>(reader: T) -> io::Result<()> {
+ let lines: Vec<String> = reader.lines().map(|l| l.unwrap()).collect();
+
+ let mut num2: i64 = 0;
+ let mut num3: i64 = 0;
+
+ for line in &lines {
+ let mut hist = HashMap::new();
+
+ for ch in line.chars() {
+ let value: i64 = *hist.get(&ch).unwrap_or(&0) + 1;
+ hist.insert(ch, value);
+ }
+
+ let mut have2 = false;
+ let mut have3 = false;
+ for &num in hist.values() {
+ if num == 2 { have2 = true; }
+ if num == 3 { have3 = true; }
+ }
+
+ num2 += have2 as i64;
+ num3 += have3 as i64;
+ }
+
+ println!("{}", num2 * num3);
+
+ // TODO: Can this be faster than n^2?
+ for line1 in &lines {
+ for line2 in &lines {
+ if !close_enough(&line1, &line2) { continue; }
+
+ let mut ans = String::new();
+
+ for (ch1, ch2) in line1.chars().zip(line2.chars()) {
+ if ch1 == ch2 {
+ ans.push(ch1);
+ }
+ }
+
+ println!("{}", ans);
+ return Ok(())
+ }
+ }
+
+ Ok(())
+}
diff --git a/2018/src/main.rs b/2018/src/main.rs
index 7e683ca..162a56e 100644
--- a/2018/src/main.rs
+++ b/2018/src/main.rs
@@ -7,10 +7,12 @@ use std::process::exit;
use argparse::{ArgumentParser, StoreTrue, Store};
mod day1;
+mod day2;
fn day_switch<T: BufRead>(day: i32, reader: T) -> io::Result<()> {
match day {
1 => day1::main(reader),
+ 2 => day2::main(reader),
_ => Err(Error::new(ErrorKind::Other, "Invalid day"))
}
}
@@ -65,13 +67,18 @@ fn main() -> io::Result<()> {
}
error_handler(||
- match day_string.parse::<i32>() {
- Ok(day) => run_day(day, &options),
- Err(_) => {
- for day in 1..1 {
- run_day(day, &options)?;
+ if day_string.len() == 0 {
+ for day in 1..3 {
+ run_day(day, &options)?;
+ }
+ Ok(())
+ } else {
+ match day_string.parse::<i32>() {
+ Ok(day) => run_day(day, &options),
+ Err(_) => {
+ println!("Invalid day argument");
+ exit(1)
}
- Ok(())
}
}
)