refactor: massive refactor to have only one binary to call

internal/2020/DayThree/code.go

@@ -0,0 +1,52 @@
+package daythree
+
+import (
+	"advent-of-code/internal/registry"
+	"os"
+	"strings"
+)
+
+func init() {
+	registry.Register("2020D3", ParseInput, PartOne, PartTwo)
+}
+
+func ParseInput(filepath string) []string {
+	content, _ := os.ReadFile(filepath)
+	return strings.Split(string(content), "\n")
+}
+
+func PartOne(input []string) int {
+	trees := 0
+	column := 0
+	for row := range input {
+		if len(input[row]) == 0 {
+			continue
+		}
+		if input[row][column%len(input[row])] == '#' {
+			trees++
+		}
+		column += 3
+	}
+	return trees
+}
+
+func PartTwo(input []string) int {
+	result := 1
+	slopes := [][]int{{1, 1}, {3, 1}, {5, 1}, {7, 1}, {1, 2}}
+	for _, slope := range slopes {
+		trees := 0
+		column := 0
+		for row := 0; row < len(input); row += slope[1] {
+			if len(input[row]) == 0 {
+				continue
+			}
+			if input[row][column%len(input[row])] == '#' {
+				trees++
+			}
+			column += slope[0]
+		}
+		result *= trees
+	}
+	return result
+}
+

internal/2020/DayThree/code_test.go

@@ -0,0 +1,34 @@
+package daythree
+
+import "testing"
+
+var testInput = []string{
+	"..##.......",
+	"#...#...#..",
+	".#....#..#.",
+	"..#.#...#.#",
+	".#...##..#.",
+	"..#.##.....",
+	".#.#.#....#",
+	".#........#",
+	"#.##...#...",
+	"#...##....#",
+	".#..#...#.#",
+}
+
+func TestPartOne(t *testing.T) {
+	expected := 7
+	got := PartOne(testInput)
+	if got != expected {
+		t.Errorf("PartOne() = %d, want %d", got, expected)
+	}
+}
+
+func TestPartTwo(t *testing.T) {
+	expected := 336
+	got := PartTwo(testInput)
+	if got != expected {
+		t.Errorf("PartTwo() = %d, want %d", got, expected)
+	}
+}
+