y2015d6

y2015/src/bin/d6.rs

@@ -0,0 +1,20 @@
+use std::fs;
+
+use y2015::days::d6;
+
+fn main() {
+    part1();
+    part2();
+}
+
+fn part1() {
+    let root = env!("CARGO_MANIFEST_DIR");
+    let content = fs::read_to_string(format!("{root}/resources/6_input.txt")).unwrap();
+    println!("{}", d6::process_part1(&content));
+}
+
+fn part2() {
+    let root = env!("CARGO_MANIFEST_DIR");
+    let content = fs::read_to_string(format!("{root}/resources/6_input.txt")).unwrap();
+    println!("{}", d6::process_part2(&content));
+}

y2015/src/days/d5.rs

@@ -67,7 +67,6 @@ pub fn process_part2(input: &str) -> i32 {
             }
             for (_, count) in pairs.into_iter() {
                 if count >= 2 {
-                    println!("{}", String::from_utf8(line.to_vec()).unwrap());
                     return 1;
                 }
             }

y2015/src/days/d6.rs

@@ -0,0 +1,117 @@
+pub fn process_part1(input: &str) -> u32 {
+    let mut grid = vec![vec![0; 1000]; 1000];
+    input.lines().for_each(|line| {
+        let words = line.split_whitespace().collect::<Vec<&str>>();
+        match words[0] {
+            "toggle" => {
+                let from = parse_coord(words[1]);
+                let to = parse_coord(words[3]);
+                toggle(&mut grid, from, to);
+            }
+            "turn" => {
+                let from = parse_coord(words[2]);
+                let to = parse_coord(words[4]);
+                match words[1] {
+                    "off" => turn_off(&mut grid, from, to),
+                    "on" => turn_on(&mut grid, from, to),
+                    _ => panic!("Should not happen"),
+                };
+            }
+            _ => panic!("Should not happen"),
+        }
+    });
+    grid.iter().map(|line| line.iter().sum::<u32>()).sum()
+}
+
+fn parse_coord(coord: &str) -> (u32, u32) {
+    let (x, y) = coord.split_once(",").unwrap();
+    (x.parse().unwrap(), y.parse().unwrap())
+}
+
+fn toggle(grid: &mut [Vec<u32>], from: (u32, u32), to: (u32, u32)) {
+    for x in from.0..=to.0 {
+        let line = grid.get_mut(x as usize).unwrap();
+        for y in from.1..=to.1 {
+            if line[y as usize] == 1 {
+                line[y as usize] = 0;
+            } else {
+                line[y as usize] = 1;
+            }
+        }
+    }
+}
+
+fn turn_on(grid: &mut [Vec<u32>], from: (u32, u32), to: (u32, u32)) {
+    for x in from.0..=to.0 {
+        let line = grid.get_mut(x as usize).unwrap();
+        for y in from.1..=to.1 {
+            line[y as usize] = 1;
+        }
+    }
+}
+
+fn turn_off(grid: &mut [Vec<u32>], from: (u32, u32), to: (u32, u32)) {
+    for x in from.0..=to.0 {
+        let line = grid.get_mut(x as usize).unwrap();
+        for y in from.1..=to.1 {
+            line[y as usize] = 0;
+        }
+    }
+}
+
+fn adjust(grid: &mut [Vec<u32>], value: i32, from: (u32, u32), to: (u32, u32)) {
+    for x in from.0..=to.0 {
+        let line = grid.get_mut(x as usize).unwrap();
+        for y in from.1..=to.1 {
+            if value > 0 {
+                line[y as usize] = line[y as usize].saturating_add(value as u32);
+            } else {
+                line[y as usize] = line[y as usize].saturating_sub(value.unsigned_abs());
+            }
+        }
+    }
+}
+
+pub fn process_part2(input: &str) -> u32 {
+    let mut grid = vec![vec![0; 1000]; 1000];
+    input.lines().for_each(|line| {
+        let words = line.split_whitespace().collect::<Vec<&str>>();
+        match words[0] {
+            "toggle" => {
+                let from = parse_coord(words[1]);
+                let to = parse_coord(words[3]);
+                adjust(&mut grid, 2, from, to);
+            }
+            "turn" => {
+                let from = parse_coord(words[2]);
+                let to = parse_coord(words[4]);
+                match words[1] {
+                    "off" => adjust(&mut grid, -1, from, to),
+                    "on" => adjust(&mut grid, 1, from, to),
+                    _ => panic!("Should not happen"),
+                };
+            }
+            _ => panic!("Should not happen"),
+        }
+    });
+    grid.iter().map(|line| line.iter().sum::<u32>()).sum()
+}
+
+#[cfg(test)]
+mod tests_6 {
+    use super::*;
+
+    const INPUT1: &str = "turn on 0,0 through 999,999";
+    const INPUT2: &str = "toggle 0,0 through 999,0";
+    const INPUT3: &str = "turn off 499,499 through 500,500";
+
+    #[test]
+    fn it_works() {
+        let result = process_part1(INPUT1);
+        assert_eq!(result, 1_000_000);
+        let result = process_part1(format!("{INPUT1}\n{INPUT2}").as_str());
+        assert_eq!(result, 999_000);
+        let result = process_part1(format!("{INPUT1}\n{INPUT2}\n{INPUT3}").as_str());
+        assert_eq!(result, 998_996);
+    }
+}

y2015/src/days/mod.rs

@@ -3,3 +3,4 @@ pub mod d2;
 pub mod d3;
 pub mod d4;
 pub mod d5;
+pub mod d6;