Redid day23 from scratch...

It's working but I'm not happy about it yet.

2019/day23-scratch/main.go

@@ -0,0 +1,123 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"strconv"
+	"strings"
+)
+
+func main() {
+	input, _ := ioutil.ReadFile("input")
+
+	// Build the memory
+	mem := map[int]int{}
+	for i, s := range strings.Split(strings.TrimSpace(string(input)), ",") {
+		mem[i], _ = strconv.Atoi(s)
+	}
+
+	// Mesage Buffers
+	in, out := make([]chan int, 50), make([]chan int, 50)
+	for i := 0; i < 50; i++ {
+		in[i], out[i] = make(chan int), make(chan int)
+		go run(mem, in[i], out[i])
+		// Send address to each computer first
+		in[i] <- i
+		in[i] <- -1
+	}
+
+	idle := 0
+	var old, nat [2]int
+
+	for i := 0; ; i = (i + 1) % 50 {
+		select {
+		case addr := <-out[i]:
+			if addr == 255 {
+				new := [2]int{<-out[i], <-out[i]}
+				if nat == [2]int{} {
+					fmt.Println(new[1])
+				}
+				nat = new
+			} else {
+				in[addr] <- <-out[i]
+				in[addr] <- <-out[i]
+			}
+			idle = 0
+		case in[i] <- -1:
+			idle++
+		}
+
+		if idle >= 50 {
+			if nat[1] == old[1] {
+				fmt.Println(nat[1])
+				return
+			}
+			in[0] <- nat[0]
+			in[0] <- nat[1]
+			old = nat
+			idle = 0
+		}
+	}
+}
+
+func run(init map[int]int, in <-chan int, out chan<- int) {
+	ip, rb := 0, 0
+	mem := map[int]int{}
+	for i, v := range init {
+		mem[i] = v
+	}
+
+	for {
+		ins := fmt.Sprintf("%05d", mem[ip])
+		op, _ := strconv.Atoi(ins[3:])
+		par := func(i int) int {
+			switch ins[3-i] {
+			case '1':
+				return ip + i
+			case '2':
+				return rb + mem[ip+i]
+			default:
+				return mem[ip+i]
+			}
+		}
+
+		switch op {
+		case 1:
+			mem[par(3)] = mem[par(1)] + mem[par(2)]
+		case 2:
+			mem[par(3)] = mem[par(1)] * mem[par(2)]
+		case 3:
+			mem[par(1)] = <-in
+		case 4:
+			out <- mem[par(1)]
+		case 5:
+			if mem[par(1)] != 0 {
+				ip = mem[par(2)]
+				continue
+			}
+		case 6:
+			if mem[par(1)] == 0 {
+				ip = mem[par(2)]
+				continue
+			}
+		case 7:
+			if mem[par(1)] < mem[par(2)] {
+				mem[par(3)] = 1
+			} else {
+				mem[par(3)] = 0
+			}
+		case 8:
+			if mem[par(1)] == mem[par(2)] {
+				mem[par(3)] = 1
+			} else {
+				mem[par(3)] = 0
+			}
+		case 9:
+			rb += mem[par(1)]
+		case 99:
+			return
+		}
+
+		ip += []int{1, 4, 4, 2, 2, 3, 3, 4, 4, 2}[op]
+	}
+}