day 18

18/18.go

@@ -0,0 +1,154 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// cat input | go run 18.go
+
+type instruction struct {
+	instr    string
+	register string
+	argIsInt bool
+	argInt   int
+	argReg   string
+}
+
+func main() {
+
+	scanner := bufio.NewScanner(os.Stdin)
+	registers := make(map[string]int)
+	var instructions = []instruction{}
+
+	for scanner.Scan() {
+		s := strings.Split(scanner.Text(), " ")
+		i := instruction{s[0], s[1], false, 0, ""}
+
+		if len(s) == 3 {
+			int, err := strconv.Atoi(s[2])
+			if err != nil {
+				i.argIsInt = false
+				i.argReg = s[2]
+			} else {
+				i.argIsInt = true
+				i.argInt = int
+			}
+		}
+
+		instructions = append(instructions, i)
+	}
+
+	pc := 0
+	lastsnd := -1
+
+loop:
+	for pc < len(instructions) && pc >= 0 {
+		fmt.Println("PC: ", pc, instructions[pc])
+		fmt.Println(registers, lastsnd)
+
+		instruction := instructions[pc].instr
+		register := instructions[pc].register
+
+		_, present := registers[register]
+		if !present {
+			registers[register] = 0
+		}
+
+		switch instruction {
+		case "set":
+			pc = instrSet(&registers, instructions[pc], pc)
+		case "add":
+			pc = instrAdd(&registers, instructions[pc], pc)
+		case "mul":
+			pc = instrMul(&registers, instructions[pc], pc)
+		case "mod":
+			pc = instrMod(&registers, instructions[pc], pc)
+		case "snd":
+			pc = instrSnd(&registers, instructions[pc], pc, &lastsnd)
+		case "rcv":
+			pc = instrRcv(&registers, instructions[pc], pc, &lastsnd)
+			break loop
+		case "jgz":
+			pc = instrJgz(&registers, instructions[pc], pc)
+		default:
+			fmt.Println("Instruction invalid!")
+		}
+		fmt.Println(registers, lastsnd)
+		pc++
+
+	}
+	fmt.Println(registers, lastsnd)
+}
+
+func instrSet(registers *map[string]int, i instruction, pc int) int {
+	r := *registers
+	if i.argIsInt {
+		r[i.register] = i.argInt
+	} else {
+		r[i.register] = r[i.argReg]
+	}
+	return pc
+}
+
+func instrAdd(registers *map[string]int, i instruction, pc int) int {
+	r := *registers
+	if i.argIsInt {
+		r[i.register] += i.argInt
+	} else {
+		r[i.register] += r[i.argReg]
+	}
+	return pc
+}
+
+func instrMul(registers *map[string]int, i instruction, pc int) int {
+	r := *registers
+	if i.argIsInt {
+		r[i.register] *= i.argInt
+	} else {
+		r[i.register] *= r[i.argReg]
+	}
+	return pc
+}
+
+func instrMod(registers *map[string]int, i instruction, pc int) int {
+	r := *registers
+	if i.argIsInt {
+		r[i.register] %= i.argInt
+	} else {
+		r[i.register] %= r[i.argReg]
+	}
+	return pc
+}
+
+func instrSnd(registers *map[string]int, i instruction, pc int, snd *int) int {
+	r := *registers
+	*snd = r[i.register]
+	fmt.Println("*snd:", *snd)
+	return pc
+}
+
+func instrRcv(registers *map[string]int, i instruction, pc int, snd *int) int {
+	r := *registers
+	if i.argIsInt && i.argInt != 0 {
+		r[i.register] = *snd
+	}
+	return pc
+}
+
+func instrJgz(registers *map[string]int, i instruction, pc int) int {
+	r := *registers
+	if i.argIsInt {
+		if r[i.register] > 0 {
+			pc = (pc + i.argInt) - 1
+		}
+	} else {
+		if r[i.register] > 0 {
+			pc = (pc + r[i.argReg]) - 1
+		}
+	}
+	return pc
+}