feat: add solutions for P1/P2 2018D1

internal/2018/DayOne/code.go

@@ -0,0 +1,45 @@
+package dayone
+
+import (
+	"advent-of-code/internal/registry"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func init() {
+	registry.Register("2018D1", ParseInput, PartOne, PartTwo)
+}
+
+func ParseInput(filepath string) []int {
+	content, _ := os.ReadFile(filepath)
+	var data []int
+	for line := range strings.SplitSeq(string(content), "\n") {
+		num, _ := strconv.Atoi(line)
+		data = append(data, num)
+	}
+	return data
+}
+
+func PartOne(data []int) int {
+	sum := 0
+	for _, num := range data {
+		sum += num
+	}
+	return sum
+}
+
+func PartTwo(data []int) int {
+	seen := make(map[int]bool)
+	sum := 0
+	seen[0] = true
+	for {
+		for _, num := range data {
+			sum += num
+			if seen[sum] {
+				return sum
+			}
+			seen[sum] = true
+		}
+	}
+}