Reimplement day 2.

2016/day-02/sample.txt

@@ -1,4 +0,0 @@
-ULL
-RRDDD
-LURDL
-UUUUD

2016/day-02/solution.rs

@@ -1,85 +0,0 @@
-use std::cmp::min;
-use std::io::prelude::*;
-use std::io::BufReader;
-use std::fs::File;
-use std::path::Path;
-use std::env;
-
-fn move_pos1(pos: i32, instruction: char) -> i32
-{
-    match instruction {
-        'U' => if pos > 3 { pos - 3 } else { pos },
-        'D' => if pos < 7 { pos + 3 } else { pos },
-        'L' => if pos % 3 != 1 { pos - 1 } else { pos },
-        'R' => if pos % 3 != 0 { pos + 1 } else { pos },
-        _   => panic!("Unsupported direction {}", instruction),
-    }
-}
-
-fn row_width(y: i32) -> i32
-{
-    min(2 * y + 1, 9 - 2 * y)
-}
-
-fn row_offset(y: i32) -> i32
-{
-    (5 - row_width(y)) / 2
-}
-
-fn is_legal(pos: (i32, i32)) -> bool {
-    let (x, y) = pos;
-    let width = row_width(y);
-    let offset = row_offset(y);
-
-    y >= 0 && y < 5 && x >= offset && x < offset + width
-}
-
-fn move_pos2(pos: (i32, i32), instruction: char) -> (i32, i32)
-{
-    let (x, y) = pos;
-    let new_pos = match instruction {
-        'U' => (x, y - 1),
-        'D' => (x, y + 1),
-        'L' => (x - 1, y),
-        'R' => (x + 1, y),
-        _   => panic!("Unsupported direction {}", instruction),
-    };
-
-    if is_legal(new_pos) { new_pos } else { pos }
-}
-
-fn pos2char(pos: (i32, i32)) -> String
-{
-    let (x, y) = pos;
-    let mut num = x + 1 - row_offset(y);
-    for i in 0..y {
-        num += row_width(i);
-    }
-
-    format!("{:X}", num)
-}
-
-fn main()
-{
-    let args: Vec<String> = env::args().collect();
-    let path = Path::new(&args[1]);
-    let f = File::open(&path).expect("Could not open file");
-    let reader = BufReader::new(f);
-
-    let mut pos1 = 5;
-    let mut pos2 = (0, 2);
-    let mut code1 = String::new();
-    let mut code2 = String::new();
-    for line in reader.lines() {
-        for instruction in line.unwrap().trim().chars() {
-            pos1 = move_pos1(pos1, instruction);
-            pos2 = move_pos2(pos2, instruction);
-        }
-
-        code1 += &pos1.to_string();
-        code2 += &pos2char(pos2);
-    }
-
-    println!("Code 1 is {}", code1);
-    println!("Code 2 is {}", code2);
-}

2016/src/day2.rs

@@ -0,0 +1,128 @@
+use std::cmp::min;
+use std::io::prelude::*;
+use std::io;
+use common;
+
+
+#[derive(Default)]
+pub struct Day2 {
+}
+
+impl Day2 {
+
+    pub fn new() -> Day2 {
+        Default::default()
+    }
+}
+
+impl common::Solution for Day2 {
+
+    fn part1(&mut self, input: &mut io::Read) -> String {
+        let reader = io::BufReader::new(input);
+        let mut pos = 5;
+        let mut code = String::new();
+
+        for line in reader.lines() {
+            for instruction in line.unwrap().trim().chars() {
+                pos = move_pos1(pos, instruction);
+            }
+            code += &pos.to_string();
+        }
+
+        code
+    }
+
+    fn part2(&mut self, input: &mut io::Read) -> String {
+        let reader = io::BufReader::new(input);
+        let mut pos = (0, 2);
+        let mut code = String::new();
+
+        for line in reader.lines() {
+            for instruction in line.unwrap().trim().chars() {
+                pos = move_pos2(pos, instruction);
+            }
+            code += &pos2char(pos);
+        }
+
+        code
+    }
+}
+
+
+fn move_pos1(pos: i32, instruction: char) -> i32
+{
+    match instruction {
+        'U' => if pos > 3 { pos - 3 } else { pos },
+        'D' => if pos < 7 { pos + 3 } else { pos },
+        'L' => if pos % 3 != 1 { pos - 1 } else { pos },
+        'R' => if pos % 3 != 0 { pos + 1 } else { pos },
+        _   => panic!("Unsupported direction {}", instruction),
+    }
+}
+
+fn row_width(y: i32) -> i32
+{
+    min(2 * y + 1, 9 - 2 * y)
+}
+
+fn row_offset(y: i32) -> i32
+{
+    (5 - row_width(y)) / 2
+}
+
+fn is_legal(pos: (i32, i32)) -> bool {
+    let (x, y) = pos;
+    let width = row_width(y);
+    let offset = row_offset(y);
+
+    y >= 0 && y < 5 && x >= offset && x < offset + width
+}
+
+fn move_pos2(pos: (i32, i32), instruction: char) -> (i32, i32)
+{
+    let (x, y) = pos;
+    let new_pos = match instruction {
+        'U' => (x, y - 1),
+        'D' => (x, y + 1),
+        'L' => (x - 1, y),
+        'R' => (x + 1, y),
+        _   => panic!("Unsupported direction {}", instruction),
+    };
+
+    if is_legal(new_pos) { new_pos } else { pos }
+}
+
+fn pos2char(pos: (i32, i32)) -> String
+{
+    let (x, y) = pos;
+    let mut num = x + 1 - row_offset(y);
+    for i in 0..y {
+        num += row_width(i);
+    }
+
+    format!("{:X}", num)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use common::Solution;
+
+    const SAMPLE: &str = "ULL
+RRDDD
+LURDL
+UUUUD";
+
+    #[test]
+    fn test_part1() {
+        let mut instance = Day2::new();
+        assert_eq!("1985", instance.part1(&mut SAMPLE.as_bytes()));
+    }
+
+    #[test]
+    fn test_part2() {
+        let mut instance = Day2::new();
+        assert_eq!("5DB3", instance.part2(&mut SAMPLE.as_bytes()));
+    }
+
+}

2016/src/main.rs

@@ -8,6 +8,7 @@ use std::io;
 
 pub mod common;
 pub mod day1;
+pub mod day2;
 pub mod day12;
 pub mod day15;
 pub mod day16;
@@ -18,6 +19,7 @@ pub mod day25;
 fn get_impl(day: &str) -> Box<common::Solution> {
     match day.parse() {
         Ok(1) => { Box::new(day1::Day1::new()) }
+        Ok(2) => { Box::new(day2::Day2::new()) }
         Ok(12) => { Box::new(day12::Day12::new()) }
         Ok(15) => { Box::new(day15::Day15::new()) }
         Ok(16) => { Box::new(day16::Day16::new()) }