updates

2024/go/day17/day17.go

@@ -0,0 +1,91 @@
+package day17
+
+import (
+	"encoding/json"
+	"fmt"
+	"regexp"
+	"strings"
+	"golang.org/x/exp/slices"
+
+
+	"adventofcode2024/utils"
+
+)
+
+type Opcode int
+
+const (
+	adv     Opcode = 0
+	bxl		Opcode = 1
+	bst   	Opcode = 2
+	jnx     Opcode = 3
+	bxc     Opcode = 4
+	out	 	Opcode = 5
+	bdv 	Opcode = 6
+	cdv 	Opcode = 7
+
+)
+
+func Part1(input string) string {	
+	m := regexp.MustCompile(`[\d,]+`).FindAllString(input, -1)
+	a := utils.MustAtoi(m[0])
+	b := utils.MustAtoi(m[1])
+	c := utils.MustAtoi(m[2])
+
+	var pgm []int
+	json.Unmarshal([]byte("["+m[3]+"]"), &pgm)
+
+	fmt.Printf("%d %d %d %v\n", a, b, c, pgm)
+	out := fmt.Sprint(run(a, b, c, pgm))
+	out = fmt.Sprint(strings.Trim(strings.ReplaceAll(out, " ", ","), "[]"))
+	return out
+}
+
+func Part2(input string) int {
+	m := regexp.MustCompile(`[\d,]+`).FindAllString(input, -1)
+	b := utils.MustAtoi(m[1])
+	c := utils.MustAtoi(m[2])
+
+	var pgm []int
+	json.Unmarshal([]byte("["+m[3]+"]"), &pgm)
+
+	fmt.Printf("%d %d %v\n", b, c, pgm)
+
+	a := 0
+	for n := len(pgm) - 1; n >= 0; n-- {
+		a <<= 3
+		for !slices.Equal(run(a, b, c, pgm), pgm[n:]) {
+			a++
+		}
+	}
+	return a
+}
+
+func run(a, b, c int, pgm []int) (output []int) {
+	for ip := 0; ip < len(pgm); ip += 2 {
+		operand := pgm[ip+1]
+		combo := []int{0, 1, 2, 3, a, b, c}[operand]
+
+		switch pgm[ip] {
+		case int(adv):
+			a >>= combo
+		case int(bxl):
+			b ^= operand
+		case int(bst):
+			b = combo % 8
+		case int(jnx):
+			if a != 0 {
+				ip = operand - 2
+			}
+		case int(bxc):
+			b ^= c
+		case int(out):
+			output = append(output, combo%8)
+		case int(bdv):
+			b = a >> combo
+		case int(cdv):
+			c = a >> combo
+		}
+	}
+	return output
+}