feat: solve part one

internal/2022/DayThree/code.go

@@ -0,0 +1,50 @@
+package daythree
+
+import (
+	"advent-of-code/internal/registry"
+	"os"
+	"strings"
+)
+
+func init() {
+	registry.Register("2022D3", ParseInput, PartOne, PartTwo)
+}
+
+func ParseInput(filepath string) []string {
+	content, _ := os.ReadFile(filepath)
+	return strings.Split(string(content), "\n")
+}
+
+func PartOne(data []string) int {
+	totalPriority := 0
+	for _, rucksack := range data {
+		compartmentSize := len(rucksack) / 2
+		firstCompartment := rucksack[:compartmentSize]
+		secondCompartment := rucksack[compartmentSize:]
+
+		firstCompartmentItems := make(map[rune]bool)
+		for _, item := range firstCompartment {
+			firstCompartmentItems[item] = true
+		}
+
+		var commonItem rune
+		for _, item := range secondCompartment {
+			if firstCompartmentItems[item] {
+				commonItem = item
+				break
+			}
+		}
+
+		if commonItem >= 'a' && commonItem <= 'z' {
+			totalPriority += int(commonItem - 'a' + 1)
+		} else if commonItem >= 'A' && commonItem <= 'Z' {
+			totalPriority += int(commonItem - 'A' + 27)
+		}
+	}
+
+	return totalPriority
+}
+
+func PartTwo(data []string) int {
+	return 0
+}