add 11 (WIP)

euler11/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "euler11"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

euler11/grid.txt

@@ -0,0 +1,20 @@
+08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08
+49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00
+81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65
+52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91
+22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80
+24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50
+32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70
+67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21
+24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72
+21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95
+78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92
+16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57
+86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58
+19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40
+04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66
+88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69
+04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36
+20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16
+20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54
+01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48

euler11/src/main.rs

@@ -0,0 +1,192 @@
+use std::{fmt::Debug, fs};
+
+const LENGTH: usize = 4;
+
+type Data = u32;
+type Neighbours = Vec<Coordinate>;
+
+struct Coordinate {
+    x: usize,
+    y: usize,
+}
+
+impl Coordinate {
+    fn new(x: usize, y: usize) -> Self {
+        Self { x, y }
+    }
+}
+
+impl Debug for Coordinate {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let inner = &format!("{},{}", self.x, self.y);
+        f.write_str(inner)
+    }
+}
+
+struct Grid {
+    grid: Vec<Vec<Data>>,
+    nx: usize,
+    ny: usize,
+    curr_x: usize,
+    curr_y: usize,
+    curr_direction: Direction,
+    done: bool,
+}
+
+impl Grid {
+    fn from_file(filename: &str) -> Self {
+        let grid: Vec<Vec<_>> = fs::read_to_string(filename)
+            .unwrap()
+            .split_terminator('\n')
+            .map(|line| {
+                line.split_whitespace()
+                    .map(|cell| cell.parse::<u8>().unwrap() as Data)
+                    .collect()
+            })
+            .collect();
+        let ny = grid.len();
+        let nx = grid[0].len();
+        Grid {
+            grid,
+            nx,
+            ny,
+            curr_x: 0,
+            curr_y: 0,
+            curr_direction: Direction::None,
+            done: false,
+        }
+    }
+
+    fn run(&mut self) {
+        let mut largest = 0;
+        loop {
+            if let Some(coordinates) = self.next() {
+                let value = coordinates.iter().map(|c| self.grid[c.y][c.x]).product();
+                if value > largest {
+                    largest = value;
+                }
+            }
+            if self.done {
+                break;
+            }
+        }
+        println!("{largest}");
+    }
+
+    fn advance_index(&mut self) {
+        if self.curr_x == self.nx - 1 {
+            self.curr_x = 0;
+            self.curr_y += 1;
+            if self.curr_y == self.ny {
+                self.done = true;
+            }
+        } else {
+            self.curr_x += 1;
+        }
+    }
+
+    fn get_neighbours(&self) -> Option<Neighbours> {
+        match self.curr_direction {
+            Direction::Down => self.get_neighbours_down(),
+            Direction::Right => self.get_neighbours_right(),
+            Direction::DiagonalUp => self.get_neighbours_diag_up(),
+            Direction::DiagonalDown => self.get_neighbours_diag_down(),
+            Direction::None => unreachable!(),
+        }
+    }
+
+    fn get_neighbours_down(&self) -> Option<Neighbours> {
+        let max_y = self.curr_y + LENGTH;
+        if max_y > self.ny {
+            None
+        } else {
+            Some(
+                (self.curr_y..max_y)
+                    .map(|y| Coordinate::new(self.curr_x, y))
+                    .collect(),
+            )
+        }
+    }
+
+    fn get_neighbours_right(&self) -> Option<Neighbours> {
+        let max_x = self.curr_x + LENGTH;
+        if max_x > self.nx {
+            None
+        } else {
+            Some(
+                (self.curr_x..max_x)
+                    .map(|x| Coordinate::new(x, self.curr_y))
+                    .collect(),
+            )
+        }
+    }
+
+    fn get_neighbours_diag_up(&self) -> Option<Neighbours> {
+        let max_x = self.curr_x + LENGTH;
+        let min_y = self.curr_y.wrapping_sub(LENGTH);
+        if max_x > self.nx || min_y > self.ny {
+            None
+        } else {
+            Some(
+                (self.curr_x..max_x)
+                    .zip(self.curr_y..min_y)
+                    .map(|(x, y)| Coordinate::new(x, y))
+                    .collect(),
+            )
+        }
+    }
+
+    fn get_neighbours_diag_down(&self) -> Option<Neighbours> {
+        let max_x = self.curr_x + LENGTH;
+        let max_y = self.curr_y + LENGTH;
+        if max_x > self.nx || max_y > self.ny {
+            None
+        } else {
+            Some(
+                (self.curr_x..max_x)
+                    .zip(self.curr_y..max_y)
+                    .map(|(x, y)| Coordinate::new(x, y))
+                    .collect(),
+            )
+        }
+    }
+}
+
+impl Iterator for Grid {
+    type Item = Neighbours;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let has_wrapped;
+        (self.curr_direction, has_wrapped) = self.curr_direction.next();
+        if has_wrapped {
+            self.advance_index();
+        };
+        self.get_neighbours()
+    }
+}
+
+#[derive(Debug)]
+enum Direction {
+    None,
+    Down,
+    Right,
+    DiagonalUp,
+    DiagonalDown,
+}
+
+impl Direction {
+    fn next(&self) -> (Self, bool) {
+        match self {
+            Direction::None => (Direction::Down, false),
+            Direction::Down => (Direction::Right, false),
+            Direction::Right => (Direction::DiagonalUp, false),
+            Direction::DiagonalUp => (Direction::DiagonalDown, false),
+            Direction::DiagonalDown => (Direction::Down, true),
+        }
+    }
+}
+
+fn main() {
+    let mut grid = Grid::from_file("grid.txt");
+    grid.run();
+}