Day 23 part 2

src/tasks/day23.rs

@@ -1,9 +1,14 @@
 use std::collections::VecDeque;
 
-use crate::tasks::day05::{IntCodeComputer, load_ram};
+use crate::tasks::day05::{IntCodeComputer, load_ram, RAM};
 
 pub fn run() {
     let ram = load_ram("input/day23.txt");
+    part1(ram.clone());
+    part2(ram.clone());
+}
+
+fn part1(ram: RAM) {
     let mut computers: Vec<IntCodeComputer> = (0..50).map(|address| IntCodeComputer::new(vec![address], ram.clone())).collect();
     let mut buffer: VecDeque<Packet> = VecDeque::new();
     loop {
@@ -18,7 +23,7 @@ pub fn run() {
 
         while let Some(packet) = buffer.pop_front() {
             if packet.destination == 255 {
-                println!("Finished with first y={} to 255", packet.y);
+                println!("Part 1: Finished with first y={} to 255", packet.y);
                 return;
             }
 
@@ -27,6 +32,53 @@ pub fn run() {
     }
 }
 
+fn part2(ram: RAM) {
+    let mut computers: Vec<IntCodeComputer> = (0..50).map(|address| IntCodeComputer::new(vec![address], ram.clone())).collect();
+    let mut buffer: VecDeque<Packet> = VecDeque::new();
+
+    let mut rounds_without_packets = 0;
+    let mut nat_content: Option<Packet> = None;
+    let mut pushed_to_first: Vec<Packet> = Vec::new();
+    loop {
+        for computer in &mut computers {
+            if computer.get_input().is_empty() {
+                computer.add_input(&[-1, -1, -1]);
+            }
+            computer.run_until_input_empty();
+            while computer.get_output().len() >= 3 {
+                buffer.push_back(Packet::from(&computer.get_output()[0..3]));
+                computer.clear_n_output(3);
+            }
+        }
+
+        if buffer.is_empty() {
+            rounds_without_packets += 1;
+        }
+        if let Some(ref energy_packet) = nat_content {
+            if rounds_without_packets > 5 {
+                if let Some(last) = pushed_to_first.last() {
+                    if last == energy_packet {
+                        println!("Part 2: Got the same packet twice. Y was {}", last.y);
+                        return;
+                    }
+                }
+                pushed_to_first.push(energy_packet.clone());
+                buffer.push_back(energy_packet.clone());
+                rounds_without_packets = 0;
+            }
+        }
+        while let Some(packet) = buffer.pop_front() {
+            if packet.destination == 255 {
+                nat_content = Some(Packet { destination: 0, x: packet.x, y: packet.y });
+                continue;
+            }
+
+            computers[packet.destination].add_input(packet.to_input().as_slice());
+        }
+    }
+}
+
+#[derive(Clone, PartialEq, Debug)]
 struct Packet {
     destination: usize,
     x: i128,