use strings.FieldFunc

remove regex and parsing functions

upd compare test

day-4/one.go

@@ -1,53 +1,29 @@
 package main
 
 import (
-	"regexp"
+	"strings"
+	"unicode"
 )
 
 type M map[string]interface{}
 
-var allCards []M
-
-var _regex_winning_numbers = regexp.MustCompile(
-	`^Card (?P<card>[\s\d]+):\s` +
-		`(?P<winning>[0-9\s]+)\s` +
-		`\|\s` +
-		`(?P<mynums>[0-9\s]+)$`)
-
-var _regex_nums = regexp.MustCompile("[0-9]+")
-
-// compareLists returns the number of matching elements between winning and mynums
-func compareLists(winningStr string, mynumsStr string) (int, error) {
-	x, err := numStrToArr(winningStr, []int{})
-	if err != nil {
-		return 0, err
-	}
-	winning := x
-	x, err = numStrToArr(mynumsStr, []int{})
-	if err != nil {
-		return 0, err
-	}
-	mynums := x
-
-	n := 0
-	for _, num := range mynums {
-		if contains(winning, num) {
-			n += 1
-		}
-	}
-	return n, nil
-}
-
 // one computes points based on matching numbers
 func one(lines []string) (int, error) {
-	for _, line := range lines {
-		parseAllCards(line)
+
+	f := func(c rune) bool {
+		return !unicode.IsDigit(c)
 	}
-	cards = make([]Card, len(lines))
 
 	sum := 0
-	for x, card := range allCards {
-		m, err := compareLists(card["winning"].(string), card["mynums"].(string))
+	cards = make([]Card, len(lines))
+	for x, line := range lines {
+		winning, mynums := func() (string, string) {
+			y := strings.Split(line, ":")
+			z := strings.Split(y[1], "|")
+			return z[0], z[1]
+		}()
+
+		m, err := compare(strings.FieldsFunc(winning, f), strings.FieldsFunc(mynums, f))
 		if err != nil {
 			return 0, err
 		}

day-4/one_test.go

@@ -1,25 +1,45 @@
 package main
 
 import (
+	"strings"
 	"testing"
+	"unicode"
 
-	"github.com/go-playground/assert/v2"
+	"github.com/go-playground/assert"
 )
 
-func TestCompareLists(t *testing.T) {
+func TestCompare(t *testing.T) {
 	//t.Skip("skipping test")
-	t.Run("Should find 4 matches", func(t *testing.T) {
-		res, _ := compareLists("41 48 83 86 17", "83 86  6 31 17  9 48 53")
-		assert.Equal(t, 4, res)
+
+	input := []string{
+		"Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53",
+		"Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19",
+	}
+
+	winning1, mynums1 := func() (string, string) {
+		y := strings.Split(input[0], ":")
+		z := strings.Split(y[1], "|")
+		return z[0], z[1]
+	}()
+
+	winning2, mynums2 := func() (string, string) {
+		y := strings.Split(input[1], ":")
+		z := strings.Split(y[1], "|")
+		return z[0], z[1]
+	}()
+
+	f := func(c rune) bool {
+		return !unicode.IsDigit(c)
+	}
+
+	res1, _ := compare(strings.FieldsFunc(winning1, f), strings.FieldsFunc(mynums1, f))
+	res2, _ := compare(strings.FieldsFunc(winning2, f), strings.FieldsFunc(mynums2, f))
+
+	t.Run("Should return 4 matches", func(t *testing.T) {
+		assert.Equal(t, 4, res1)
 	})
 
-	t.Run("Should find 2 matches", func(t *testing.T) {
-		res, _ := compareLists(" 1 21 53 59 44 ", "69 82 63 72 16 21 14  1")
-		assert.Equal(t, 2, res)
-	})
-
-	t.Run("Should find 0 matches", func(t *testing.T) {
-		res, _ := compareLists("87 83 26 28 32", "88 30 70 12 93 22 82 36")
-		assert.Equal(t, 0, res)
+	t.Run("Should return 2 matches", func(t *testing.T) {
+		assert.Equal(t, 2, res2)
 	})
 }

day-4/util.go

@@ -5,7 +5,6 @@ import (
 	"log"
 	"math"
 	"os"
-	"strconv"
 )
 
 // readlines reads lines from stdin.
@@ -25,29 +24,18 @@ func readlines() []string {
 	return lines
 }
 
-func parseAllCards(line string) {
-	groups := M{}
-	res := _regex_winning_numbers.FindStringSubmatch(line)
-	names := _regex_winning_numbers.SubexpNames()
-	for i := range res {
-		groups[names[i]] = res[i]
+// compare returns the number of matching elements
+func compare(a []string, b []string) (int, error) {
+	n := 0
+	for _, elem := range a {
+		if contains(b, elem) {
+			n += 1
 		}
-	allCards = append(allCards, groups)
+	}
+	return n, nil
 }
 
-// numStrToArr converts a string of numbers or an array of numbers
-func numStrToArr(nums string, arr []int) ([]int, error) {
-	for _, num := range _regex_nums.FindAllString(nums, -1) {
-		n, err := strconv.Atoi(num)
-		if err != nil {
-			return []int{}, err
-		}
-		arr = append(arr, n)
-	}
-	return arr, nil
-}
-
-// contains returns true if an slice of elements contains a given element
+// contains returns true if a slice of elements contains a given element
 func contains[T comparable](elems []T, v T) bool {
 	for _, s := range elems {
 		if v == s {