feat: add main code

2021/day01/go.mod

@@ -0,0 +1,3 @@
+module 2021/day01
+
+go 1.25.4

2021/day01/main.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func parseInput(file string) []int {
+	content, err := os.ReadFile(file)
+	if err != nil {
+		log.Fatalf("Failed to read input file: %v", err)
+	}
+	var data []int
+	for line := range strings.SplitSeq(string(content), "\n") {
+		num, err := strconv.Atoi(line)
+		if err != nil {
+			log.Fatalf("Failed to convert string to int: %v", err)
+		}
+		data = append(data, num)
+	}
+	return data
+}
+
+func PartOne(data []int) int {
+	count := 0
+	for i := 1; i < len(data); i++ {
+		if data[i] > data[i-1] {
+			count++
+		}
+	}
+	return count
+}
+
+func PartTwo(data []int) int {
+	count := 0
+	for i := 3; i < len(data); i++ {
+		if data[i] > data[i-3] {
+			count++
+		}
+	}
+	return count
+}
+
+func main() {
+	data := parseInput("input.txt")
+	fmt.Println("Part 1:", PartOne(data))
+	fmt.Println("Part 2:", PartTwo(data))
+}

2021/day01/main_test.go

@@ -0,0 +1,21 @@
+package main
+
+import "testing"
+
+var testInput = []int{199, 200, 208, 210, 200, 207, 240, 269, 260, 263}
+
+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 := 5
+	got := PartTwo(testInput)
+	if got != expected {
+		t.Errorf("PartTwo() = %d, want %d", got, expected)
+	}
+}