Finished aoc year 2015 day 3

advent_of_code/2015/3/src/main.rs

@@ -0,0 +1,69 @@
+use std::{borrow::BorrowMut, collections::HashSet};
+
+fn solve_first(input: &str) -> usize {
+    let mut coord = (0, 0);
+    let mut visited = HashSet::new();
+    visited.insert(coord);
+
+    for c in input.chars() {
+        match c {
+            '>' => coord.0 += 1,
+            '<' => coord.0 -= 1,
+            '^' => coord.1 += 1,
+            'v' => coord.1 -= 1,
+            _ => (),
+        }
+
+        visited.insert(coord);
+    }
+
+    visited.len()
+}
+
+fn solve_second(input: &str) -> usize {
+    let mut santa_coord = (0, 0);
+    let mut robo_coord = (0, 0);
+
+    let mut visited = HashSet::new();
+    visited.insert(santa_coord);
+
+    for (idx, c) in input.chars().enumerate() {
+        let coord = if idx % 2 == 0 {
+            santa_coord.borrow_mut()
+        } else {
+            robo_coord.borrow_mut()
+        };
+
+        match c {
+            '>' => coord.0 += 1,
+            '<' => coord.0 -= 1,
+            '^' => coord.1 += 1,
+            'v' => coord.1 -= 1,
+            _ => (),
+        }
+
+        visited.insert(coord.clone());
+    }
+
+    visited.len()
+}
+
+fn main() {
+    println!("Hello, this is Patrick!");
+
+    let input_txt = include_str!("../input.txt");
+
+    let result_first = solve_first(input_txt);
+
+    println!(
+        "The number of houses that receive at least one present is {}",
+        result_first
+    );
+
+    let result_second = solve_second(input_txt);
+
+    println!(
+        "The number of houses that receive at least one present in the year after is {}",
+        result_second
+    );
+}