added day 19

vlanx · vlanx · commit bfbfe0976afb · 2024-10-22T22:11:02.000+01:00
diff --git a/2018/day19/input.txt b/2018/day19/input.txt
@@ -0,0 +1,37 @@
+#ip 2
+addi 2 16 2
+seti 1 0 1
+seti 1 3 3
+mulr 1 3 5
+eqrr 5 4 5
+addr 5 2 2
+addi 2 1 2
+addr 1 0 0
+addi 3 1 3
+gtrr 3 4 5
+addr 2 5 2
+seti 2 6 2
+addi 1 1 1
+gtrr 1 4 5
+addr 5 2 2
+seti 1 1 2
+mulr 2 2 2
+addi 4 2 4
+mulr 4 4 4
+mulr 2 4 4
+muli 4 11 4
+addi 5 6 5
+mulr 5 2 5
+addi 5 19 5
+addr 4 5 4
+addr 2 0 2
+seti 0 7 2
+setr 2 6 5
+mulr 5 2 5
+addr 2 5 5
+mulr 2 5 5
+muli 5 14 5
+mulr 5 2 5
+addr 4 5 4
+seti 0 7 0
+seti 0 3 2
diff --git a/2018/day19/nineteen.go b/2018/day19/nineteen.go
@@ -0,0 +1,124 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+func main() {
+	instructions := instructions()
+	// IP = 2
+	registers := [6]int{0, 0, 0, 0, 0, 0}
+	registers = runProgram(instructions[1:], registers)
+	fmt.Printf("Part 1 | When the program halts, the value %d is in register[%d]\n", registers[0], 0)
+	fmt.Printf("Part 2 | When the program halts, the value %d is in register[%d]\n", part2(), 0)
+}
+
+func runProgram(program []string, registers [6]int) [6]int {
+	ip := registers[2]
+	for ip < len(program) {
+		registers = decode(program[ip], registers)
+		registers[2]++
+		// Update IP counter
+		ip = registers[2]
+	}
+	return registers
+}
+
+func decode(instruction string, registers [6]int) [6]int {
+	fields := [3]int{}
+	inst := ""
+	fmt.Sscanf(instruction, "%s %2d %2d %2d", &inst, &fields[0], &fields[1], &fields[2])
+
+	switch inst {
+	case "seti":
+		registers = seti(registers, fields)
+	case "setr":
+		registers = setr(registers, fields)
+	case "addi":
+		registers = addi(registers, fields)
+	case "addr":
+		registers = addr(registers, fields)
+	case "muli":
+		registers = muli(registers, fields)
+	case "mulr":
+		registers = mulr(registers, fields)
+	case "gtrr":
+		registers = gtrr(registers, fields)
+	case "eqrr":
+		registers = eqrr(registers, fields)
+	default:
+		fmt.Printf("inst: %s not found\n", inst)
+	}
+
+	return registers
+}
+
+func addr(registers [6]int, instructions [3]int) [6]int {
+	registers[instructions[2]] = registers[instructions[0]] + registers[instructions[1]]
+	return registers
+}
+
+func addi(registers [6]int, instructions [3]int) [6]int {
+	registers[instructions[2]] = registers[instructions[0]] + instructions[1]
+	return registers
+}
+
+func seti(registers [6]int, instructions [3]int) [6]int {
+	registers[instructions[2]] = instructions[0]
+	return registers
+}
+
+func setr(registers [6]int, instructions [3]int) [6]int {
+	registers[instructions[2]] = registers[instructions[0]]
+	return registers
+}
+
+func mulr(registers [6]int, instructions [3]int) [6]int {
+	registers[instructions[2]] = registers[instructions[0]] * registers[instructions[1]]
+	return registers
+}
+
+func muli(registers [6]int, instructions [3]int) [6]int {
+	registers[instructions[2]] = registers[instructions[0]] * instructions[1]
+	return registers
+}
+
+func gtrr(registers [6]int, instructions [3]int) [6]int {
+	if registers[instructions[0]] > registers[instructions[1]] {
+		registers[instructions[2]] = 1
+	} else {
+		registers[instructions[2]] = 0
+	}
+	return registers
+}
+
+func eqrr(registers [6]int, instructions [3]int) [6]int {
+	if registers[instructions[0]] == registers[instructions[1]] {
+		registers[instructions[2]] = 1
+	} else {
+		registers[instructions[2]] = 0
+	}
+	return registers
+}
+
+func instructions() []string {
+	f, _ := os.ReadFile("input.txt")
+	lines := strings.Split(strings.TrimSpace(string(f)), "\n")
+	return lines
+}
+
+// I can't be arsed to disassemble assembly what was meticulously crafted lol. Got this off Github
+func part2() int {
+	numberToFactorize := 10551387 // this index varies based on inputs
+
+	var ans int
+	for i := 1; i <= numberToFactorize; i++ {
+		if numberToFactorize%i == 0 {
+			ans += i
+		}
+	}
+
+	return ans
+}
