From b084f178eeb7390fd788b29978ed04db450f8596 Mon Sep 17 00:00:00 2001
From: Dreaded_X <tim@huizinga.dev>
Date: Sat, 10 Dec 2022 17:39:13 +0100
Subject: [PATCH] Improved 2022 - Day 8 by stopping early if the highest
 possible score can not exceed the current highest score

---
 2022/src/bin/day8.rs | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/2022/src/bin/day8.rs b/2022/src/bin/day8.rs
index e975e3e..d086724 100644
--- a/2022/src/bin/day8.rs
+++ b/2022/src/bin/day8.rs
@@ -125,6 +125,11 @@ impl aoc::Solver for Day {
                 let mut distance_up = 0;
                 let mut distance_down = 0;
 
+                // Bail early if the tree can not exceed the current highest
+                if x * (input[y].len()-x-1) * y * (input.len()-y-1) < score_highest {
+                    continue;
+                }
+
                 for c in (0..x).rev() {
                     distance_left += 1;
                     if input[y][c] >= height {
@@ -132,6 +137,10 @@ impl aoc::Solver for Day {
                     }
                 }
 
+                if distance_left * (input[y].len()-x-1) * y * (input.len()-y-1) < score_highest {
+                    continue;
+                }
+
                 for c in x+1..input[y].len() {
                     distance_right += 1;
                     if input[y][c] >= height {
@@ -139,6 +148,10 @@ impl aoc::Solver for Day {
                     }
                 }
 
+                if distance_left * distance_right * y * (input.len()-y-1) < score_highest {
+                    continue;
+                }
+
                 for r in (0..y).rev() {
                     distance_up += 1;
                     if input[r][x] >= height {
@@ -146,6 +159,10 @@ impl aoc::Solver for Day {
                     }
                 }
 
+                if distance_left * distance_right * distance_up * (input.len()-y-1) < score_highest {
+                    continue;
+                }
+
                 for r in y+1..input[y].len() {
                     distance_down += 1;
                     if input[r][x] >= height {