From eb1e1a5120e3029cbf0c1892290e2b42944bfb59 Mon Sep 17 00:00:00 2001
From: Daniel Bulant <danbulant@gmail.com>
Date: Sun, 17 Dec 2023 00:59:57 +0100
Subject: [PATCH] working optimizations

---
 2023/16/src/main.rs | 44 ++++++++++++++++++++++++++++++++++++++------
 1 file changed, 38 insertions(+), 6 deletions(-)

diff --git a/2023/16/src/main.rs b/2023/16/src/main.rs
index 6b2599d..c2a4585 100644
--- a/2023/16/src/main.rs
+++ b/2023/16/src/main.rs
@@ -1,8 +1,29 @@
-use std::{fs::File, io::{BufReader, BufRead, Write}, ops::Add, fmt::Debug, collections::HashSet, hash::{Hasher, BuildHasherDefault}};
+use std::{fs::File, io::{BufReader, BufRead, Write}, ops::Add, fmt::Debug, collections::HashSet, hash::{Hasher, BuildHasherDefault}, process::exit};
 
 fn main() {
     part1();
     part2();
+    // let mut values = HashSet::new();
+    // for x in 0..110 {
+    //     for y in 0..110 {
+    //         let vecs = [
+    //             VEC_RIGHT,
+    //             VEC_LEFT,
+    //             VEC_UP,
+    //             VEC_DOWN
+    //         ];
+    //         for vec in vecs {
+    //             // let vecval = ((vec.x+2)*vec.x.abs()+(vec.y+3)*vec.y.abs() - 1) as usize;
+    //             let vecval = (vec.x+1)*vec.x.abs()+(vec.y+2)*vec.y.abs();
+    //             let val = (x * 111 + y + 1) << 2 | vecval as usize;
+    //             println!("{} {} {:?} val={} vecval(plex)={}", x, y, vec, val, vecval);
+    //             if !values.insert(val) {
+    //                 println!("Collision at {},{} with {:?} {}", x, y, vec, val);
+    //                 exit(1);
+    //             }
+    //         }
+    //     }
+    // }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -47,9 +68,15 @@ struct Beam {
     vector: Vector
 }
 
+// const VECTOR_VALUES_HASH: [usize; 13] = [
+//     0, 0, 0, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3
+// ];
+
 impl Beam {
-    fn to_u64(&self) -> u64 {
-        (self.point.x * 100 + self.point.y) * (1 + self.vector.x + 2 * (self.vector.y + 1))
+    fn to_u64(&self) -> usize {
+        let vecval = (self.vector.x+1)*self.vector.x.abs()+(self.vector.y+2)*self.vector.y.abs();
+        let val = (self.point.x * 110 + self.point.y + 1) << 2 | vecval as usize;
+        val
     }
 }
 
@@ -253,9 +280,11 @@ fn setup() -> (Point, Vec<Vec<MapPoint>>, Vec<Vec<MapPoint>>) {
 
 fn get_count(max_point: Point, rows: Vec<Vec<MapPoint>>, columns: Vec<Vec<MapPoint>>, beam: Beam) -> usize {
     let mut energized : Vec<Vec<bool>> = vec![vec![false; max_point.x]; max_point.y];
-    let mut beams_set = HashSet::<Beam, BuildHasherDefault<BeamHasher>>::default();
+    // let mut beams_set = HashSet::<Beam, BuildHasherDefault<BeamHasher>>::default();
+    let mut beams_set_vec = vec![false; (max_point.x + 1) * (max_point.y + 1) * 4];
     let mut beams : Vec<Beam> = vec![beam];
-    beams_set.insert(beams[0]);
+    // beams_set.insert(beams[0]);
+    beams_set_vec[beams[0].to_u64()] = true;
 
     let mut offset = 0;
 
@@ -307,7 +336,10 @@ fn get_count(max_point: Point, rows: Vec<Vec<MapPoint>>, columns: Vec<Vec<MapPoi
                             vector: v
                         };
                         // append_if_not_in(&mut beams, beam);
-                        if beams_set.insert(beam) {
+                        // if beams_set.insert(beam) {
+                        let bnum = beam.to_u64();
+                        if beams_set_vec[bnum] == false {
+                            beams_set_vec[bnum] = true;
                             beams.push(beam);
                         }
                     }