From 9b098af432c0be0cecd3cb7671d0d5e38e4b7351 Mon Sep 17 00:00:00 2001
From: Mika Suhonen <mikas@mikas.net>
Date: Mon, 2 Dec 2024 17:03:01 +0200
Subject: [PATCH] p1

---
 2024/02/go.mod  |   3 ++
 2024/02/main.go | 102 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 105 insertions(+)
 create mode 100644 2024/02/go.mod
 create mode 100644 2024/02/main.go

diff --git a/2024/02/go.mod b/2024/02/go.mod
new file mode 100644
index 0000000..3a3a5a6
--- /dev/null
+++ b/2024/02/go.mod
@@ -0,0 +1,3 @@
+module main
+
+go 1.23.3
diff --git a/2024/02/main.go b/2024/02/main.go
new file mode 100644
index 0000000..cebd75d
--- /dev/null
+++ b/2024/02/main.go
@@ -0,0 +1,102 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const (
+	Increasing = 1
+	Decreasing = -1
+)
+
+func absInt(x int) int {
+	return absDiffInt(x, 0)
+}
+
+func absDiffInt(x, y int) int {
+	if x < y {
+		return y - x
+	}
+	return x - y
+}
+
+func checkDirection(x int) int {
+	switch {
+	case x < 0:
+		return Increasing
+	case x > 0:
+		return Decreasing
+	default:
+		return 0
+	}
+}
+
+func checklevel(report []int) bool {
+	dir := checkDirection(report[0] - report[1])
+	for i := 0; i < len(report)-1; i++ {
+		zero := report[i]
+		one := report[i+1]
+		diff := zero - one
+		if newDir := checkDirection(diff); newDir != dir {
+			return false
+		}
+		absDiff := absInt(diff)
+		if absDiff < 1 || absDiff > 3 {
+			return false
+		}
+	}
+	return true
+}
+
+func main() {
+
+	lines, err := parse()
+	if err != nil {
+		fmt.Println("Error:", err)
+	}
+
+	var safes = 0
+
+	for _, line := range lines {
+		fmt.Println(line)
+		numbers := strings.Fields(line)
+		report := make([]int, len(numbers))
+		for i, num := range numbers {
+			x, err := strconv.Atoi(num)
+			if err != nil {
+				panic(err)
+			}
+			report[i] = x
+		}
+		if checklevel(report) {
+			safes++
+		}
+
+	}
+
+	fmt.Println(safes)
+
+}
+
+func parse() ([]string, error) {
+	if len(os.Args) < 2 {
+		return nil, fmt.Errorf("no file provided")
+	}
+	filePath := os.Args[1]
+	data, err := os.ReadFile(filePath)
+	if err != nil {
+		return nil, fmt.Errorf("error opening file: %v", err)
+	}
+	chunks := strings.Split(string(data), "\n")
+	var nonEmpthyChunks = []string{}
+
+	for _, chunk := range chunks {
+		if chunk != "" {
+			nonEmpthyChunks = append(nonEmpthyChunks, chunk)
+		}
+	}
+	return nonEmpthyChunks, nil
+}