day8part1 done... part 2 might require another approach

08/main.rs

@@ -0,0 +1,88 @@
+#![allow(dead_code)]
+use std::fs::File;
+use std::io;
+use std::io::BufRead;
+use std::path::Path;
+use std::time::Instant;
+
+#[derive(Debug, Clone)]
+struct Tree(i8, bool);
+
+fn main() {
+    let now = Instant::now();
+    part_one();
+    let part_one_duration = now.elapsed();
+    part_two();
+    let part_two_duration = now.elapsed();
+    println!(
+        "p1: {}ms, p2: {}ms",
+        part_one_duration.as_millis(),
+        (part_two_duration - part_one_duration).as_millis()
+    );
+}
+
+fn read_lines<P>(filename: P) -> io::Result<io::Lines<io::BufReader<File>>>
+where
+    P: AsRef<Path>,
+{
+    // note that this discards a final newline
+    let file = File::open(filename)?;
+    Ok(io::BufReader::new(file).lines())
+}
+
+fn part_one() {
+    let mut grid: Vec<Vec<Tree>> = vec![];
+    let mut total = 0;
+    if let Ok(lines) = read_lines("./inputs/input") {
+        for (i, line) in lines.enumerate() {
+            if let Ok(row) = line {
+                grid.push(vec![]);
+                let mut max = -1;
+                for c in row.chars() {
+                    if (c as i8) - 48 > max {
+                        total += 1;
+                        max = (c as i8) - 48;
+                        grid[i].push(Tree((c as i8) - 48, true));
+                    } else {
+                        grid[i].push(Tree((c as i8) - 48, false));
+                    }
+                }
+                max = -1;
+                let invert = grid[i].len() - 1;
+                for (j, t) in grid[i].clone().iter().rev().enumerate() {
+                    if t.0 > max {
+                        if !grid[i][invert - j].1 {
+                            total += 1;
+                        }
+                        max = t.0;
+                        grid[i][invert - j] = Tree(t.0, true);
+                    }
+                }
+            }
+        }
+    }
+    let invert = grid.len() - 1;
+    for i in 0..grid.len() {
+        let mut in_max = -1;
+        let mut out_max = -1;
+        for j in 0..grid.len() {
+            if grid[j][i].0 > in_max {
+                if !grid[j][i].1 {
+                    total += 1;
+                }
+                in_max = grid[j][i].0;
+                grid[j][i] = Tree(grid[j][i].0, true);
+            }
+            if grid[invert - j][i].0 > out_max {
+                if !grid[invert - j][i].1 {
+                    total += 1;
+                }
+                out_max = grid[invert - j][i].0;
+                grid[invert - j][i] = Tree(grid[invert - j][i].0, true);
+            }
+        }
+    }
+    println!("{}", total);
+}
+
+fn part_two() {}