2023/day-1/main.go

@@ -3,10 +3,12 @@ package main
 import (
 	"fmt"
 	"log"
+
+	"codeflow.dananglin.me.uk/apollo/advent-of-code/internal/common"
 )
 
 func main() {
-	document, err := calibrationDocument("2023/day-1/files/input")
+	document, err := common.ReadFile("2023/day-1/files/input")
 	if err != nil {
 		log.Fatalf("Error: Unable to retrieve the calibration document; %v", err)
 	}

2023/day-1/part_one.go

@@ -1,11 +1,5 @@
 package main
 
-import (
-	"bufio"
-	"fmt"
-	"os"
-)
-
 func partOneCalculateSumCalibrationValues(document []string) int {
 	sum := 0
 
@@ -31,25 +25,3 @@ func calibrationValue(line string) int {
 
 	return (10 * digits[0]) + digits[len(digits)-1]
 }
-
-func calibrationDocument(filename string) ([]string, error){
-	file, err := os.Open(filename)
-	if err != nil {
-		return nil, fmt.Errorf("unable to open %q; %w", filename, err)
-	}
-	defer file.Close()
-
-	var lines []string
-
-	scanner := bufio.NewScanner(file)
-
-	for scanner.Scan() {
-		lines = append(lines, scanner.Text())
-	}
-
-	if err := scanner.Err(); err != nil {
-		return nil, fmt.Errorf("error scanning %q; %w", filename, err)
-	}
-
-	return lines, nil
-}

2023/day-2/main.go

@@ -1,16 +1,16 @@
 package main
 
 import (
-	"bufio"
 	"fmt"
 	"log"
-	"os"
+
+	"codeflow.dananglin.me.uk/apollo/advent-of-code/internal/common"
 )
 
 func main() {
 	filename := "2023/day-2/files/input"
 
-	games, err := readFile(filename)
+	games, err := common.ReadFile(filename)
 	if err != nil {
 		log.Fatalf("ERROR: unable to read from %s, %v\n", filename, err)
 	}
@@ -115,21 +115,3 @@ func fewestSet(sets []Set) Set {
 
 	return result
 }
-
-func readFile(filename string) ([]string, error) {
-	file, err := os.Open(filename)
-	if err != nil {
-		return nil, fmt.Errorf("unable to open %s, %w", filename, err)
-	}
-
-	defer file.Close()
-
-	scanner := bufio.NewScanner(file)
-	var content []string
-
-	for scanner.Scan() {
-		content = append(content, scanner.Text())
-	}
-
-	return content, nil
-}

2023/day-3/main.go

@@ -1,12 +1,12 @@
 package main
 
 import (
-	"bufio"
 	"fmt"
 	"log"
-	"os"
 	"strconv"
 	"unicode"
+
+	"codeflow.dananglin.me.uk/apollo/advent-of-code/internal/common"
 )
 
 const (
@@ -20,7 +20,7 @@ type solution struct {
 }
 
 func main() {
-	schematic, err := engineSchematic("2023/day-3/files/input")
+	schematic, err := common.ReadFile("2023/day-3/files/input")
 	if err != nil {
 		log.Fatalf("ERROR: Unable to retrieve the engine schematic; %v\n", err)
 	}
@@ -138,22 +138,6 @@ func fixTheGondola(schematic []string) (solution, error) {
 	return answer, nil
 }
 
-func engineSchematic(filename string) ([]string, error) {
-	file, err := os.Open(filename)
-	if err != nil {
-		return nil, fmt.Errorf("unable to open %q; %w", filename, err)
-	}
-
-	scanner := bufio.NewScanner(file)
-	var lines []string
-
-	for scanner.Scan() {
-		lines = append(lines, scanner.Text())
-	}
-
-	return lines, nil
-}
-
 func isSymbol(r rune) bool {
 	return !unicode.IsDigit(r) && (r != dot)
 }

2023/day-4/main.go

@@ -1,12 +1,12 @@
 package main
 
 import (
-	"bufio"
 	"fmt"
 	"log"
-	"os"
 	"strings"
 	"unicode"
+
+	"codeflow.dananglin.me.uk/apollo/advent-of-code/internal/common"
 )
 
 type cardResult struct {
@@ -20,7 +20,7 @@ type solution struct {
 }
 
 func main() {
-	cards, err := cardPack("2023/day-4/files/input")
+	cards, err := common.ReadFile("2023/day-4/files/input")
 	if err != nil {
 		log.Fatalf("ERROR: Unable to retrieve the pack of scratchcards; %v\n", err)
 	}
@@ -149,24 +149,3 @@ func cardScore(card string) (cardResult, error) {
 
 	return result, nil
 }
-
-func cardPack(filename string) ([]string, error) {
-	file, err := os.Open(filename)
-	if err != nil {
-		return nil, fmt.Errorf("unable to open %q; %w", filename, err)
-	}
-	defer file.Close()
-
-	scanner := bufio.NewScanner(file)
-	var cards []string
-
-	for scanner.Scan() {
-		cards = append(cards, scanner.Text())
-	}
-
-	if err := scanner.Err(); err != nil {
-		return nil, fmt.Errorf("error scanning %q; %w", filename, err)
-	}
-
-	return cards, nil
-}

internal/common/common.go

@@ -0,0 +1,65 @@
+package common
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"unicode"
+)
+
+func ReadFile(filename string) ([]string, error) {
+	file, err := os.Open(filename)
+	if err != nil {
+		return nil, fmt.Errorf("unable to open %q; %w", filename, err)
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	var lines []string
+
+	for scanner.Scan() {
+		lines = append(lines, scanner.Text())
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, fmt.Errorf("error scanning %q; %w", filename, err)
+	}
+
+	return lines, nil
+}
+
+func ParseIntList(line string) ([]int, error) {
+	var values []int
+	digitString := ""
+
+	addValue := func(digit string) error {
+		if len(digit) > 0 {
+			value, err := strconv.Atoi(digit)
+			if err != nil {
+				return fmt.Errorf("unable to parse %q to int; %w", digit, err)
+			}
+			values = append(values, value)
+		}
+
+		return nil
+	}
+
+	for i, v := range line {
+		if unicode.IsDigit(v) {
+			digitString = digitString + string(v)
+			if i == len(line)-1 {
+				if err := addValue(digitString); err != nil {
+					return nil, fmt.Errorf("unable to add %q to the list of ints; %w", digitString, err)
+				}
+			}
+		} else {
+			if err := addValue(digitString); err != nil {
+				return nil, fmt.Errorf("unable to add %q to the list of ints; %w", digitString, err)
+			}
+			digitString = ""
+		}
+	}
+
+	return values, nil
+}

internal/common/common_test.go

@@ -0,0 +1,33 @@
+package common
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestParseIntList(t *testing.T) {
+	table := []struct {
+		list string
+		want []int
+	}{
+		{
+			list: "87 2 435 89 100 1 0 16534",
+			want: []int{87, 2, 435, 89, 100, 1, 0, 16534},
+		},
+		{
+			list: "145, 834, 66, 2, 90, 123",
+			want: []int{145, 834, 66, 2, 90, 123},
+		},
+	}
+
+	for i := range table {
+		got, err := ParseIntList(table[i].list)
+		if err != nil {
+			t.Fatalf("received an error after running ParseIntList(); %v", err)
+		}
+
+		if !reflect.DeepEqual(got, table[i].want) {
+			t.Errorf("unexpected result received from ParseIntList(); want %v, got %v", table[i].want, got)
+		}
+	}
+}