update

december_15/src/main.rs

@@ -5,7 +5,7 @@ use std::io::prelude::*;
 
 const RADIX: u32 = 10;
 
-static mut shortest: u32 = 99999;
+static mut shortest: u32 = 60000;
 
 fn main(){
     let file = File::open("./input.txt").expect("Read failed");
@@ -36,9 +36,9 @@ fn main(){
 
 fn get_shortest_weight(weight_vec: &Vec<Vec<u32>>, x: usize, y: usize, current_weight: u32, width: usize, height: usize, visited: &Vec<(usize, usize)>) {
     let mut visited_local = visited.to_owned();
-    
     unsafe {
-        if current_weight > shortest {
+        if visited_local.contains(&(x,y)) || current_weight > shortest || visited_local.len() > 1000{
+            //println!("Breaking at {}, {}, {}", current_weight, visited_local.len(), shortest);
             return;
         }
     }
@@ -47,10 +47,6 @@ fn get_shortest_weight(weight_vec: &Vec<Vec<u32>>, x: usize, y: usize, current_w
         println!("Current length: {}, shortest now: {}", current_weight, shortest);}
         return;
     }
-    
-    if visited_local.contains(&(x,y)) {
-        return;
-    }
     visited_local.push((x,y));
     
     let temp_weight = current_weight + weight_vec[y][x];

december_16/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "december_16"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+hex = "0.4.3"

december_16/example.txt

@@ -0,0 +1 @@
+D2FE28

december_16/src/main.rs

@@ -0,0 +1,25 @@
+use std::fs::read_to_string;
+
+extern crate hex;
+
+fn main() {
+    let input_char_vec = read_to_string("./example.txt").expect("ERROR reading file");
+    //let split_input: Vec<char> = input_char_vec.chars().collect();
+    let test  = hex::decode(input_char_vec).expect("Decoding failed");
+
+    let mut bit_vec: Vec<bool> = Vec::new();
+
+    for t in test{
+        for n in 0..8 {
+            bit_vec.push( (t >> 7-n & 1) == 1);
+        }
+    }
+    process_packet(bit_vec);
+    println!();
+}
+
+fn process_packet(bit_vec: Vec<bool>) {
+    let version = (bit_vec[0] as u32 * 4) + (bit_vec[1] as u32 * 2) + (bit_vec[2] as u32);
+    let packet_type = (bit_vec[3] as u32 * 4) + (bit_vec[4] as u32 * 2) + (bit_vec[5] as u32);
+    println!("Packet Version: {}, Packet type: {}", version, packet_type);
+}