From d8dbdca4468c9ea81bc557c6afcce4fb8140552a Mon Sep 17 00:00:00 2001
From: Ray Slakinski <ray.slakinski@gmail.com>
Date: Tue, 1 Dec 2020 14:33:20 -0500
Subject: [PATCH] day 1 optimizations, day 2 setup

---
 2020/day_1/src/main.rs | 40 +++++++++++++++++++++-------------------
 2020/day_2/Cargo.toml  |  9 +++++++++
 2020/day_2/src/main.rs |  3 +++
 3 files changed, 33 insertions(+), 19 deletions(-)
 create mode 100644 2020/day_2/Cargo.toml
 create mode 100644 2020/day_2/src/main.rs

diff --git a/2020/day_1/src/main.rs b/2020/day_1/src/main.rs
index d1109f8..da68b49 100644
--- a/2020/day_1/src/main.rs
+++ b/2020/day_1/src/main.rs
@@ -1,33 +1,35 @@
-use std::io::Read;
 fn main() {
-    let mut file = std::fs::File::open("input1").unwrap();
-    let mut contents = String::new();
-    file.read_to_string(&mut contents).unwrap();
+    // let mut file = std::fs::File::open("input1").unwrap();
+    // let mut contents = String::new();
+    // file.read_to_string(&mut contents).unwrap();
     let mut v: Vec<i32> = Vec::new();
+    let contents = std::fs::read_to_string("input1").unwrap();
     for s in contents.lines() {
         v.push(s.parse::<i32>().unwrap());
     }
     v.sort();
-    let v2 = v.to_vec();
     for n in v.iter() {
-        for n2 in v2.iter() {
-            let val = n + n2;
-            if val == 2020 {
-                print!("{} + {} = {}\n", n, n2, val);
-                print!("{} * {} = {}\n", n, n2, n * n2);
-            }
+        let k = 2020 - n;
+        if v.contains(&k) {
+            print!("{} + {} = {}\n", n, k, n + k);
+            print!("{} * {} = {}\n", n, k, n * k);
+            break;
         }
     }
-    let v3 = v.to_vec();
+
+    let mut found = false;
     for n in v.iter() {
-        for n2 in v2.iter() {
-            for n3 in v3.iter() {
-                let val = n + n2 + n3;
-                if val == 2020 {
-                    print!("{} + {} + {} = {}\n", n, n2, n3, val);
-                    print!("{} * {} * {} = {}\n", n, n2, n3, n * n2 * n3);
-                }
+        for n2 in v.iter() {
+            let k = 2020 - n - n2;
+            if v.contains(&n) && v.contains(n2) && v.contains(&k) {
+                print!("{} + {} + {} = {}\n", n, n2, k, n + n2 + k);
+                print!("{} * {} * {} = {}\n", n, n2, k, n * n2 * k);
+                found = true;
+                break;
             }
         }
+        if found {
+            break;
+        }
     }
 }
diff --git a/2020/day_2/Cargo.toml b/2020/day_2/Cargo.toml
new file mode 100644
index 0000000..2c2b156
--- /dev/null
+++ b/2020/day_2/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "day_2"
+version = "0.1.0"
+authors = ["Ray Slakinski <ray.slakinski@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/2020/day_2/src/main.rs b/2020/day_2/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/2020/day_2/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}