1 files changed, 53 insertions, 0 deletions
diff --git a/2018/src/bin/day_2.rs b/2018/src/bin/day_2.rs
new file mode 100644
index 0000000..7700871
--- /dev/null
+++ b/2018/src/bin/day_2.rs
@@ -0,0 +1,53 @@
+extern crate advent_of_code_2018;
+use advent_of_code_2018::*;
+
+use std::error::Error;
+use std::path::PathBuf;
+
+extern crate im_rc;
+use im_rc::HashMap;
+
+// cargo watch -cs "cargo run --release --bin day_2"
+
+fn main() -> Result<(), Box<Error>> {
+    let input = read_file(&PathBuf::from("inputs/2.txt"))?;
+
+    println!("Input: {:?}", input);
+    
+    let (twice, thrice) = input.iter().fold((0,0), |(twice, thrice), next| {
+        let occurances = next.chars().fold(HashMap::new(), |occurances, c| {
+            let counter = occurances.get(&c).cloned().unwrap_or(0);
+            occurances.update(c, counter + 1)
+        });
+        let has_twice = occurances.values().any(|count| *count == 2);
+        let has_thrice = occurances.values().any(|count| *count == 3);
+
+        (
+            twice + if has_twice { 1 } else { 0 },
+            thrice + if has_thrice { 1 } else { 0 },
+        )
+    });
+    
+    println!("Twice: {}", twice);
+    println!("Thrice: {}", thrice);
+    
+    let checksum = twice * thrice;
+    println!("Checksum: {}", checksum);
+
+    for i in &input {
+        for j in &input {
+            let diff = i.chars().zip(j.chars()).fold(0, |diff, (x, y)| {
+                if x != y {
+                    diff + 1
+                } else {
+                    diff
+                }
+            });
+            if diff == 1 {
+                println!("Diff of 1: {} + {}", i, j);
+            }
+        }
+    }
+    
+    Ok(())
+}