refactor: massive refactor to have only one binary to call

internal/2020/DayFive/code.go

@@ -0,0 +1,79 @@
+package dayfive
+
+import (
+	"advent-of-code/internal/registry"
+	"os"
+	"strings"
+)
+
+func init() {
+	registry.Register("2020D5", ParseInput, PartOne, PartTwo)
+}
+
+func calculateSeatID(pass string) int {
+	if len(pass) < 10 {
+		return -1
+	}
+	rowStr := pass[:7]
+	columnStr := pass[7:10]
+
+	row := 0
+	for idx, char := range rowStr {
+		if char == 'B' {
+			row |= 1 << (6 - idx)
+		}
+	}
+
+	column := 0
+	for idx, char := range columnStr {
+		if char == 'R' {
+			column |= 1 << (2 - idx)
+		}
+	}
+
+	return row*8 + column
+}
+
+func ParseInput(filepath string) []string {
+	content, _ := os.ReadFile(filepath)
+	return strings.Split(string(content), "\n")
+}
+
+func PartOne(input []string) int {
+	maxSeatID := 0
+	for _, pass := range input {
+		seatID := calculateSeatID(pass)
+		if seatID > maxSeatID {
+			maxSeatID = seatID
+		}
+	}
+	return maxSeatID
+}
+
+func PartTwo(input []string) int {
+	seatIDs := make(map[int]bool)
+	minSeatID := 1000
+	maxSeatID := 0
+
+	for _, pass := range input {
+		if len(pass) < 10 {
+			continue
+		}
+		seatID := calculateSeatID(pass)
+		seatIDs[seatID] = true
+		if seatID < minSeatID {
+			minSeatID = seatID
+		}
+		if seatID > maxSeatID {
+			maxSeatID = seatID
+		}
+	}
+
+	for seatID := minSeatID + 1; seatID < maxSeatID; seatID++ {
+		if !seatIDs[seatID] && seatIDs[seatID-1] && seatIDs[seatID+1] {
+			return seatID
+		}
+	}
+
+	return 0
+}