From 4a1745eb923031ffe75f275d8b3a2ded8a867257 Mon Sep 17 00:00:00 2001
From: Martin Ashby <martin@ashbysoft.com>
Date: Thu, 22 Dec 2022 23:16:37 +0000
Subject: day18 pt1

---
 src/day18.rs | 44 ++++++++++++++++++++++++++++++++++++++++++++
 src/main.rs  |  6 ++++--
 2 files changed, 48 insertions(+), 2 deletions(-)
 create mode 100644 src/day18.rs

(limited to 'src')

diff --git a/src/day18.rs b/src/day18.rs
new file mode 100644
index 0000000..636b342
--- /dev/null
+++ b/src/day18.rs
@@ -0,0 +1,44 @@
+fn adjescent(p: &(usize,usize,usize)) -> Vec<(usize,usize,usize)> {
+    let mut v = vec![];
+    v.push((p.0+1,p.1,p.2));
+    v.push((p.0,p.1+1,p.2));
+    v.push((p.0,p.1,p.2+1));
+    if p.0 > 0 {
+        v.push((p.0-1,p.1,p.2));
+    }
+    if p.1 > 0 {
+        v.push((p.0,p.1-1,p.2));
+    }
+    if p.2 > 0 {
+        v.push((p.0,p.1,p.2-1));
+    }
+    v
+}
+
+pub fn run(input:String) {
+    let cubes = input.lines()
+    .map(|line| {
+        let res = line.split(",").map(|t| {t.parse::<usize>().unwrap()}).collect::<Vec<usize>>();
+        if res.len() != 3 {
+            panic!("malformatted line! {}", line);
+        }
+        (res[0], res[1], res[2])
+    }).collect::<Vec<(usize,usize,usize)>>();
+    let mx: usize = cubes.iter().map(|t| {vec![t.0, t.1, t.2]}).flatten().max().unwrap() + 3;
+    // Allocate a 3d space..
+    let mut grid: Vec<Vec<Vec<bool>>> = (0..mx).map(|_| {(0..mx).map(|_| {(0..mx).map(|_| {false}).collect()}).collect()}).collect();
+    for cube in cubes.iter() {
+        grid[cube.0][cube.1][cube.2] = true;
+    }
+    // Now count cubes. Each contributes 6,minus number of connections
+    let surface_area: usize = cubes.iter().map(|cube| {
+        let mut score = 6;
+        for p in adjescent(cube) {
+            if grid[p.0][p.1][p.2] {
+                score -= 1;
+            }
+        }
+        score
+    }).sum();
+    println!("Day 18: {}", surface_area);
+}
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index 47f41a7..e865636 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -19,7 +19,8 @@ use std::fs;
 // mod day14;
 // mod day15;
 // mod day16;
-mod day17;
+//mod day17;
+mod day18;
 
 fn main() {
     // day1::run(fs::read_to_string("input/day1.txt").expect("Failed to read input file!"));
@@ -38,5 +39,6 @@ fn main() {
     // day14::run(fs::read_to_string("input/day14.txt").expect("Failed to read input file!"));
     // day15::run(fs::read_to_string("input/day15.txt").expect("Failed to read input file!"));
     // day16::run(fs::read_to_string("input/day16.txt").expect("Failed to read input file!"));
-    day17::run(fs::read_to_string("input/day17.txt").expect("Failed to read input file!"));
+    //day17::run(fs::read_to_string("input/day17.txt").expect("Failed to read input file!"));
+    day18::run(fs::read_to_string("input/day18.txt").expect("Failed to read input file!"));
 }
-- 
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