first commit

day-01/internal/one/solve.go

@@ -0,0 +1,50 @@
+package one
+
+import (
+	"bufio"
+	"bytes"
+	"embed"
+	"io"
+	"math"
+	"regexp"
+
+	"github.com/onyx-and-iris/aoc2024/day-01/internal/util"
+)
+
+//go:embed testdata
+var files embed.FS
+
+var reNums = regexp.MustCompile(`[0-9]+`)
+
+func Solve() (int, error) {
+	data, _ := files.ReadFile("testdata/input.txt")
+
+	r := bytes.NewReader(data)
+	left, right, err := parseLines(r)
+	if err != nil {
+		return 0, err
+	}
+
+	var sum int
+	for i, n := range left {
+		sum += int(math.Abs(float64(n - right[i])))
+	}
+	return sum, nil
+}
+
+func parseLines(r io.Reader) ([]int, []int, error) {
+	var left, right []int
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		nums := reNums.FindAllString(scanner.Text(), -1)
+		left = util.InsertSorted(left, util.MustConv(nums[0]))
+		right = util.InsertSorted(right, util.MustConv(nums[1]))
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, nil, err
+	}
+
+	return left, right, nil
+}