Day 1!

1 files changed, 49 insertions, 1 deletions

diff --git a/01/src/main.rs b/01/src/main.rs
index 480e6db..a46ee99 100644
--- a/01/src/main.rs
+++ b/01/src/main.rs
@@ -2,7 +2,55 @@ use advent_lib::prelude::*;
 
 
 fn main() -> Result<()> {
-  advent_lib::greeting()?;
+  let mut args = std::env::args();
+  if args.len() != 2 {
+    eprintln!("Usage: advent input");
+  }
+  let _ = args.next();
+  let filename = args.next().unwrap();
+
+  let mut input = advent_lib::read_int_file(&filename)?;
+  input.sort();
+
+  for i in 0 .. input.len() {
+    let a = input[i];
+    if a > 2020 {
+      break;
+    }
+
+    for j in i+1 .. input.len() {
+      let b = input[j];
+
+      if a + b == 2020 {
+        let product = a * b;
+        println!("a: {:?}, b: {:?}, a*b: {:?}", a, b, product);
+      }
+    }
+  }
+
+  for i in 0 .. input.len() {
+    let a = input[i];
+    if a > 2020 {
+      break;
+    }
+
+    for j in i+1 .. input.len() {
+      let b = input[j];
+
+      if a + b > 2020 {
+        break;
+      }
+
+      for k in j+1 .. input.len() {
+        let c = input[k];
+
+        if a + b + c == 2020 {
+          let product = a * b * c;
+          println!("a: {:?}, b: {:?}, c: {:?}, a*b*c: {:?}", a, b, c, product);
+        }
+      }
+    }
+  }
 
   Ok(())
 }