day18: reading instructions & hanging

day18/lagoon.go

@@ -12,28 +12,26 @@ import (
 func Run() int {
 	log.Println("hello day 18")
 	log.Println("problem of lagoon bgins")
-	filename := "day18/input"
+	filename := "day18/example"
-	instructions := ReadInstructionas(filename)
+	instructions := ReadInstructionas2(filename)
 	h, w := calcHeightWidth(instructions)
-	log.Printf("read %d instructions", len(instructions))
+	log.Printf("read %+v instructions", instructions)
 
 	field := CreateField(h, w)
 	log.Println("created field")
 
 	// fmt.Println(field.String())
-
 	field.digByInstructions(instructions)
 
+	// fmt.Println(field.String())
 	// WriteToFile("borders.txt", field.String())
 	// convert -size 3000x6000 xc:white -font "FreeMono" -pointsize 13 -fill black -draw @borders.txt borders.png
 
-	// fmt.Println(field.String())
-	// i'll start at (0,0), let's first just dig out the thing and check result
 	field.digInsides()
 
+	// fmt.Println(field.Height, field.Width)
 	// WriteToFile("fulldug.txt", field.String())
 	// convert -size 3000x6000 xc:white -font "FreeMono" -pointsize 13 -fill black -draw @fulldug.txt fulldug.png
-	// fmt.Println(field.Height, field.Width)
 
 	return field.countDugOut()
 }
@@ -115,6 +113,43 @@ func ReadInstruction(line string) Instruction {
 	return Instruction{Direction: direction, Steps: steps, Color: color}
 }
 
+func ReadInstructionas2(filename string) (result []Instruction) {
+	bytes, err := os.ReadFile(filename)
+	if err != nil {
+		panic(fmt.Sprint("error reading file: ", filename))
+	}
+	text := strings.TrimSpace(string(bytes))
+	for _, line := range strings.Split(text, "\n") {
+		result = append(result, ReadInstruction2(line))
+	}
+
+	return
+}
+
+func ReadInstruction2(line string) Instruction {
+	fields := strings.Fields(line)
+
+	hexDist := fields[2][2 : len(fields[2])-2]
+	hexDirection := fields[2][len(fields[2])-2:len(fields[2])-1]
+	var direction Direction
+	switch hexDirection {
+	case "0": direction = Rightward
+	case "1": direction = Downward
+	case "2": direction = Leftward
+	case "3": direction = Upward
+	}
+
+	dist, err := strconv.ParseUint(hexDist, 16, 64)
+	if err != nil {
+		panic(err)
+	}
+
+	return Instruction{
+		Steps: int(dist),
+		Direction: direction,
+	}
+}
+
 func calcHeightWidth(instructions []Instruction) (height, width int) {
 	movements := make(map[Direction]int)
 	for _, instr := range instructions {