day 17 part 1 solution

solutions/alessio/day17/day17.go

@@ -0,0 +1,113 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+)
+
+func check(e error) {
+	if e != nil {
+		panic(e)
+	}
+}
+
+func getComboOpVal(operand int, a int, b int, c int) int {
+	if operand >= 7 || operand < 0 {
+		panic("invalid combo operand value: " + string(operand))
+	}
+	switch operand {
+	case 4:
+		return a
+	case 5:
+		return b
+	case 6:
+		return c
+	default:
+		return operand
+	}
+}
+
+func exec(opcode int, operand int, a *int, b *int, c *int) bool {
+	switch opcode {
+	case 0: // adv
+		opVal := getComboOpVal(operand, *a, *b, *c)
+		res := (*a) / (1 << opVal)
+		*a = res
+	case 1: // bxl
+		(*b) = (*b) ^ operand
+	case 2: // bst
+		opVal := getComboOpVal(operand, *a, *b, *c)
+		(*b) = opVal % 8
+	case 3: // jnz
+		if (*a) != 0 {
+			return true
+		}
+	case 4: // bxc
+		(*b) = (*b) ^ (*c)
+	case 5: // out
+		opVal := getComboOpVal(operand, *a, *b, *c)
+		fmt.Printf("%d,", opVal%8)
+	case 6: // bdv
+		opVal := getComboOpVal(operand, *a, *b, *c)
+		res := (*a) / (1 << opVal)
+		*b = res
+	case 7: // cdv
+		opVal := getComboOpVal(operand, *a, *b, *c)
+		res := (*a) / (1 << opVal)
+		*c = res
+	default:
+		panic("invalid opcode: " + string(opcode))
+	}
+
+	return false
+}
+
+func solve(lines []string) {
+	var a, b, c int
+	fmt.Sscanf(lines[0], "Register A: %d", &a)
+	fmt.Sscanf(lines[1], "Register B: %d", &b)
+	fmt.Sscanf(lines[2], "Register C: %d", &c)
+
+	cmdstr := strings.Split(strings.Split(lines[4], ": ")[1], ",")
+	cmds := make([]int, 0, len(cmdstr))
+	for _, s := range cmdstr {
+		n, _ := strconv.Atoi(s)
+		cmds = append(cmds, n)
+	}
+
+	ptr := 0
+	for ptr <= len(cmds)-1 {
+		jump := exec(cmds[ptr], cmds[ptr+1], &a, &b, &c)
+		if jump {
+			ptr = cmds[ptr+1]
+		} else {
+			ptr += 2
+		}
+	}
+}
+
+func part1(lines []string) {
+	solve(lines)
+
+}
+
+func part2(lines []string) {
+	solve(lines)
+}
+
+func main() {
+	data, err := os.ReadFile("./input17_def.txt")
+	check(err)
+	dataStr := strings.ReplaceAll(string(data), "\r\n", "\n")
+	lines := strings.Split(strings.Trim(dataStr, "\n"), "\n")
+
+	start := time.Now()
+	part1(lines)
+	fmt.Printf("part1: %s\n", time.Since(start))
+	start = time.Now()
+	part2(lines)
+	fmt.Printf("part2: %s\n", time.Since(start))
+}

solutions/alessio/day17/go.mod

@@ -0,0 +1,10 @@
+module aoc17
+
+go 1.23
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/testify v1.10.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

solutions/alessio/day17/go.sum

@@ -0,0 +1,9 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
+github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

solutions/alessio/day17/input17.txt

@@ -0,0 +1,5 @@
+Register A: 729
+Register B: 0
+Register C: 0
+
+Program: 0,1,5,4,3,0

solutions/alessio/day17/input17_def.txt

@@ -0,0 +1,5 @@
+Register A: 35200350
+Register B: 0
+Register C: 0
+
+Program: 2,4,1,2,7,5,4,7,1,3,5,5,0,3,3,0