Day 8

Cargo.toml

@@ -9,3 +9,4 @@ edition = "2021"
 aoc-runner = "0.3.0"
 aoc-runner-derive = "0.3.0"
 id_tree = "1.8.0"
+simple-grid = "2.1.1"

src/day08.rs

@@ -0,0 +1,115 @@
+use aoc_runner_derive::{aoc, aoc_generator};
+use simple_grid::{Grid, GridIndex};
+
+#[aoc_generator(day8)]
+fn input_generator(input: &str) -> Grid<isize> {
+    let mut grid = Grid::new_default(0, 0);
+    for row in input.lines().map(|line| {
+        line.chars()
+            .map(|c| c.to_string().parse().unwrap())
+            .collect()
+    }) {
+        grid.push_row(row);
+    }
+    grid
+}
+
+#[aoc(day8, part1)]
+fn solve_part1(input: &Grid<isize>) -> usize {
+    let mut vis_grid = Grid::new_default(input.width(), input.height());
+    for row in 1..input.height() - 1 {
+        let mut max_height = *input.get(GridIndex::new(0, row)).unwrap();
+        for column in 1..input.width() - 1 {
+            let idx = GridIndex::new(column, row);
+            let height = *input.get(idx).unwrap();
+            if height > max_height {
+                *vis_grid.get_mut(idx).unwrap() = true;
+                max_height = height;
+            }
+        }
+    }
+    for row in 1..input.height() - 1 {
+        let mut max_height = *input.get(GridIndex::new(input.width() - 1, row)).unwrap();
+        for column in (1..input.width() - 1).rev() {
+            let idx = GridIndex::new(column, row);
+            let height = *input.get(idx).unwrap();
+            if height > max_height {
+                *vis_grid.get_mut(idx).unwrap() = true;
+                max_height = height;
+            }
+        }
+    }
+    for column in 1..input.width() - 1 {
+        let mut max_height = *input.get(GridIndex::new(column, 0)).unwrap();
+        for row in 1..input.height() - 1 {
+            let idx = GridIndex::new(column, row);
+            let height = *input.get(idx).unwrap();
+            if height > max_height {
+                *vis_grid.get_mut(idx).unwrap() = true;
+                max_height = height;
+            }
+        }
+    }
+    for column in 1..input.width() - 1 {
+        let mut max_height = *input
+            .get(GridIndex::new(column, input.height() - 1))
+            .unwrap();
+        for row in (1..input.height() - 1).rev() {
+            let idx = GridIndex::new(column, row);
+            let height = *input.get(idx).unwrap();
+            if height > max_height {
+                *vis_grid.get_mut(idx).unwrap() = true;
+                max_height = height;
+            }
+        }
+    }
+    vis_grid.cell_iter().filter(|&&item| item).count()
+        + dbg!((input.width() * 2) + ((input.height() - 2) * 2))
+}
+
+#[aoc(day8, part2)]
+fn solve_part2(input: &Grid<isize>) -> usize {
+    let mut max_score = 0;
+    for row in input.rows() {
+        for column in input.columns() {
+            let idx = GridIndex::new(column, row);
+            let height = *input.get(idx).unwrap();
+            let mut down_count = ((row + 1)..input.height()) // Look down
+                .map(|row| GridIndex::new(column, row))
+                .take_while(|&idx| *input.get(idx).unwrap() < height)
+                .count();
+            if down_count < input.height() - (row + 1) {
+                down_count += 1;
+            }
+            let mut up_count = (0..row) // Look up
+                .rev()
+                .map(|row| GridIndex::new(column, row))
+                .take_while(|&idx| *input.get(idx).unwrap() < height)
+                .count();
+            if up_count < row {
+                up_count += 1;
+            }
+            let mut right_count = ((column + 1)..input.width()) // Look right
+                .map(|column| GridIndex::new(column, row))
+                .take_while(|&idx| *input.get(idx).unwrap() < height)
+                .count();
+            if right_count < input.width() - (column + 1) {
+                right_count += 1;
+            }
+            let mut left_count = (0..column) // Look left
+                .rev()
+                .map(|column| GridIndex::new(column, row))
+                .take_while(|&idx| *input.get(idx).unwrap() < height)
+                .count();
+            if left_count < column {
+                left_count += 1;
+            }
+            let score = down_count * up_count * right_count * left_count;
+
+            if score > max_score {
+                max_score = score;
+            }
+        }
+    }
+    max_score
+}

src/lib.rs

@@ -7,5 +7,6 @@ mod day04;
 mod day05;
 mod day06;
 mod day07;
+mod day08;
 
 aoc_lib! { year = 2022 }