Added day3

src/day2/1.rs

@@ -1,4 +1,3 @@
-#![feature(iterator_try_collect)]
 #![feature(test)]
 extern crate test;
 

src/day2/2.rs

@@ -1,4 +1,3 @@
-#![feature(iterator_try_collect)]
 #![feature(test)]
 extern crate test;
 

src/day3/1.rs

@@ -0,0 +1,47 @@
+#![feature(test)]
+extern crate test;
+
+use std::collections::HashSet;
+
+const INPUTS: [&str; 2] = [include_str!("./sample.txt"), include_str!("./input.txt")];
+
+fn parse(input: &'static str) -> Vec<char> {
+    input.trim().chars().collect()
+}
+
+fn solution(input: Vec<char>) -> usize {
+    let mut set = HashSet::new();
+    let (mut sx, mut sy) = (0, 0);
+
+    for c in input {
+        match c {
+            'v' => sx += 1,
+            '>' => sy += 1,
+            '^' => sx -= 1,
+            '<' => sy -= 1,
+
+            _ => (),
+        }
+
+        set.insert((sx, sy));
+    }
+
+    set.len()
+}
+
+fn main() {
+    for input in INPUTS.iter() {
+        let output = parse(input);
+        let output = solution(output);
+        println!("{output}");
+    }
+}
+
+#[bench]
+fn solution_bench(b: &mut test::Bencher) {
+    b.iter(|| {
+        let input = parse(INPUTS[1]);
+        let result = solution(input);
+        test::black_box(result);
+    })
+}

src/day3/2.rs

@@ -0,0 +1,58 @@
+#![feature(test)]
+extern crate test;
+
+use std::collections::HashSet;
+
+const INPUTS: [&str; 2] = [include_str!("./sample.txt"), include_str!("./input.txt")];
+
+fn parse(input: &'static str) -> Vec<char> {
+    input.trim().chars().collect()
+}
+
+fn solution(input: Vec<char>) -> usize {
+    let mut set = HashSet::new();
+    let (mut sx, mut sy) = (0, 0);
+    let (mut rsx, mut rsy) = (0, 0);
+
+    set.insert((sx, sy));
+
+    for (i, c) in input.into_iter().enumerate() {
+        match (i % 2, c) {
+            (1, 'v') => rsx += 1,
+            (1, '>') => rsy += 1,
+            (1, '^') => rsx -= 1,
+            (1, '<') => rsy -= 1,
+            (0, 'v') => sx += 1,
+            (0, '>') => sy += 1,
+            (0, '^') => sx -= 1,
+            (0, '<') => sy -= 1,
+
+            _ => (),
+        }
+
+        if i % 2 == 0 {
+            set.insert((sx, sy));
+        } else {
+            set.insert((rsx, rsy));
+        }
+    }
+
+    set.len()
+}
+
+fn main() {
+    for input in INPUTS.iter() {
+        let output = parse(input);
+        let output = solution(output);
+        println!("{output}");
+    }
+}
+
+#[bench]
+fn solution_bench(b: &mut test::Bencher) {
+    b.iter(|| {
+        let input = parse(INPUTS[1]);
+        let result = solution(input);
+        test::black_box(result);
+    })
+}

src/day3/sample.txt

@@ -0,0 +1 @@
+^>v<