moved code around so each year is a package.

2018/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name="aoc2018"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+core = { path = "../core" }

2018/src/bin/2018_01a.rs

@@ -0,0 +1,30 @@
+// Starting with a frequency of zero, what is the resulting frequency after all of the changes in
+// frequency have been applied?
+
+use std::collections::HashMap;
+use core::read_data;
+
+fn main() {
+    let mut running_total = 0i32;
+    let binding = read_data("2018_01_data.txt");
+    let lines = binding.lines();
+    for line in lines {
+        let (direction, value) = line.split_at(1);
+        let num_val: i32 = value.parse().unwrap();
+
+        println!("Line = {line} -> {direction}||{num_val}");
+        match direction {
+            "-" => {
+                running_total -= num_val;
+            }
+            "+" => {
+                running_total += num_val;
+            }
+            _ => {
+                unreachable!("bad location");
+            }
+        }
+    }
+    println!("Final value = {running_total}");
+}
+// 533

2018/src/bin/2018_01b.rs

@@ -0,0 +1,36 @@
+// do part 1a but figure out the first repeated value
+
+use std::collections::HashMap;
+use core::read_data;
+
+fn main() {
+    let mut visited_locations: HashMap<i32, i32> = HashMap::from([(0, 0)]);
+    // let binding = read_data("2018_01_data.txt");
+    // let lines = binding.lines();
+    let lines = "-6\n+3\n+8\n+5\n-6".to_string();
+    let mut working_value = 0i32;
+
+    for line in lines.lines() {
+        let (direction, velocity) = line.split_at(1);
+        // println!("{line} split to ||{direction}|| and ||{velocity}||");
+        let direction_val : i32 = velocity.parse().unwrap();
+        match direction {
+            "+" => {
+                working_value += direction_val;
+            }
+            "-" => {
+                working_value -= direction_val;
+            }
+            _ => {
+                unreachable!("Invalid direction");
+            }
+        }
+        print!("{working_value}\t");
+        if let Some(found) = visited_locations.get(&working_value)  {
+            println!("GET SUCCESS -> {working_value} / {found}");
+            break;
+        }
+        visited_locations.insert(working_value, 0);
+    }
+}
+// BROKEN