Combine AoC Repos

2015/day23/main.go

@@ -0,0 +1,103 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var registers map[string]int
+
+func main() {
+	registers = make(map[string]int)
+	if len(os.Args) > 1 {
+		if os.Args[1] == "-help" {
+			fmt.Println("Usage: day23 [register presets]")
+			fmt.Println("  Register presets are given in the form:")
+			fmt.Println("    name=value")
+			fmt.Println("  If more than one, separate with spaces.")
+			fmt.Println("  If none are given, all registers start at 0")
+			os.Exit(1)
+		}
+		for i := range os.Args {
+			if strings.Contains(os.Args[i], "=") {
+				presets := strings.Split(os.Args[i], "=")
+				registers[presets[0]] = mustAtoi(presets[1])
+			}
+		}
+	}
+	var input []string
+	scanner := bufio.NewScanner(os.Stdin)
+	for scanner.Scan() {
+		input = append(input, strings.ToLower(scanner.Text()))
+	}
+	// We manually manage i
+	var i, cnt int
+	for i < len(input) {
+		printRegisters()
+		fmt.Print(" ")
+		cnt++
+		fmt.Print(input[i])
+		parts := strings.Split(input[i], " ")
+		switch parts[0] {
+		case "hlf":
+			registers[parts[1]] = registers[parts[1]] / 2
+			i++
+		case "tpl":
+			registers[parts[1]] = registers[parts[1]] * 3
+			i++
+		case "inc":
+			registers[parts[1]]++
+			i++
+		case "jmp":
+			i += mustAtoi(parts[1])
+		case "jie":
+			parts[1] = string(parts[1][len(parts[1])-2])
+			if registers[parts[1]]%2 == 0 {
+				i += mustAtoi(parts[2])
+			} else {
+				i++
+			}
+		case "jio":
+			parts[1] = string(parts[1][len(parts[1])-2])
+			if registers[parts[1]] == 1 {
+				i += mustAtoi(parts[2])
+			} else {
+				i++
+			}
+		}
+		fmt.Print(" ")
+		printRegistersLn()
+	}
+	printRegistersLn()
+}
+
+func printRegistersLn() {
+	printRegisters()
+	fmt.Println()
+}
+
+func printRegisters() {
+	fmt.Print("[")
+	for k := range registers {
+		printRegister(k)
+		fmt.Print(" ")
+	}
+	fmt.Print("]")
+}
+
+func printRegister(n string) {
+	fmt.Print(n + ": " + strconv.Itoa(registers[n]))
+}
+
+func mustAtoi(s string) int {
+	var i int
+	var err error
+	if i, err = strconv.Atoi(s); err != nil {
+		fmt.Println("Tried to atoi " + s)
+		os.Exit(1)
+	}
+	return i
+}