day 8

2 files changed, 146 insertions, 0 deletions

diff --git a/src/2022/8/mod.rs b/src/2022/8/mod.rs
new file mode 100644
index 0000000..59f561c
--- /dev/null
+++ b/src/2022/8/mod.rs
@@ -0,0 +1,142 @@
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+use crate::prelude::*;
+
+pub fn parse(fh: File) -> Result<Grid<u8>> {
+    Ok(parse::digit_grid(parse::lines(fh)))
+}
+
+pub fn part1(trees: Grid<u8>) -> Result<i64> {
+    let mut total = 0;
+    for row in (0..trees.rows().0).map(Row) {
+        'tree: for col in (0..trees.cols().0).map(Col) {
+            let tree = trees[row][col];
+
+            if (0..col.0).map(Col).all(|col| trees[row][col] < tree) {
+                total += 1;
+                continue 'tree;
+            }
+            if ((col.0 + 1)..trees.cols().0)
+                .map(Col)
+                .all(|col| trees[row][col] < tree)
+            {
+                total += 1;
+                continue 'tree;
+            }
+            if (0..row.0).map(Row).all(|row| trees[row][col] < tree) {
+                total += 1;
+                continue 'tree;
+            }
+            if ((row.0 + 1)..trees.rows().0)
+                .map(Row)
+                .all(|row| trees[row][col] < tree)
+            {
+                total += 1;
+                continue 'tree;
+            }
+        }
+    }
+    Ok(total)
+}
+
+pub fn part2(trees: Grid<u8>) -> Result<i64> {
+    let mut max = 0;
+    for row in (0..trees.rows().0).map(Row) {
+        for col in (0..trees.cols().0).map(Col) {
+            let tree = trees[row][col];
+
+            let mut seen = false;
+            let left = (0..col.0)
+                .map(Col)
+                .rev()
+                .take_while(|col| {
+                    if seen {
+                        return false;
+                    }
+
+                    let other = trees[row][*col];
+                    if other < tree {
+                        true
+                    } else {
+                        seen = true;
+                        true
+                    }
+                })
+                .count();
+
+            let mut seen = false;
+            let right = ((col.0 + 1)..trees.cols().0)
+                .map(Col)
+                .take_while(|col| {
+                    if seen {
+                        return false;
+                    }
+
+                    let other = trees[row][*col];
+                    if other < tree {
+                        true
+                    } else {
+                        seen = true;
+                        true
+                    }
+                })
+                .count();
+
+            let mut seen = false;
+            let up = (0..row.0)
+                .map(Row)
+                .rev()
+                .take_while(|row| {
+                    if seen {
+                        return false;
+                    }
+
+                    let other = trees[*row][col];
+                    if other < tree {
+                        true
+                    } else {
+                        seen = true;
+                        true
+                    }
+                })
+                .count();
+
+            let mut seen = false;
+            let down = ((row.0 + 1)..trees.rows().0)
+                .map(Row)
+                .take_while(|row| {
+                    if seen {
+                        return false;
+                    }
+
+                    let other = trees[*row][col];
+                    if other < tree {
+                        true
+                    } else {
+                        seen = true;
+                        true
+                    }
+                })
+                .count();
+
+            let scenic = left * right * up * down;
+            if scenic > max {
+                max = scenic;
+            }
+        }
+    }
+    Ok(max.try_into().unwrap())
+}
+
+#[test]
+fn test() {
+    assert_eq!(
+        part1(parse(parse::data(2022, 8).unwrap()).unwrap()).unwrap(),
+        1851
+    );
+    assert_eq!(
+        part2(parse(parse::data(2022, 8).unwrap()).unwrap()).unwrap(),
+        574080
+    );
+}
diff --git a/src/2022/mod.rs b/src/2022/mod.rs
index c6beea8..e6faf0c 100644
--- a/src/2022/mod.rs
+++ b/src/2022/mod.rs
@@ -14,6 +14,8 @@ mod day5;
 mod day6;
 #[path = "7/mod.rs"]
 mod day7;
+#[path = "8/mod.rs"]
+mod day8;
 // NEXT MOD
 
 pub fn run(day: u8, puzzle: u8) -> Result<i64> {
@@ -33,6 +35,8 @@ pub fn run(day: u8, puzzle: u8) -> Result<i64> {
         (6, 2) => day6::part2(day6::parse(parse::data(2022, 6)?)?),
         (7, 1) => day7::part1(day7::parse(parse::data(2022, 7)?)?),
         (7, 2) => day7::part2(day7::parse(parse::data(2022, 7)?)?),
+        (8, 1) => day8::part1(day8::parse(parse::data(2022, 8)?)?),
+        (8, 2) => day8::part2(day8::parse(parse::data(2022, 8)?)?),
         // NEXT PART
         _ => Err(anyhow!("unknown puzzle {}-{}", day, puzzle)),
     }