From 44e82799b8b91c3e195be6c43a124701501b5c12 Mon Sep 17 00:00:00 2001
From: Gregory <neogen570@gmail.com>
Date: Mon, 7 Feb 2022 22:00:52 +0200
Subject: [PATCH] day2

---
 d2/d2.go      | 42 ++++++++++++++++++++++++++++++++++++++++++
 d2/d2_test.go | 20 ++++++++++++++++++++
 main.go       |  2 ++
 3 files changed, 64 insertions(+)
 create mode 100644 d2/d2.go
 create mode 100644 d2/d2_test.go

diff --git a/d2/d2.go b/d2/d2.go
new file mode 100644
index 0000000..e2849a6
--- /dev/null
+++ b/d2/d2.go
@@ -0,0 +1,42 @@
+package d2
+
+import (
+	"log"
+	"strconv"
+	"strings"
+)
+
+type position struct {
+	x int64
+	y int64
+}
+
+func D2(input string) int64 {
+	position := position{}
+	directions := strings.Split(strings.TrimSpace(input), "\n")
+
+	for _, direction := range directions {
+		directionAndValue := strings.Split(strings.TrimSpace(direction), " ")
+
+		if len(directionAndValue) != 2 {
+			log.Fatal("line has wrong number of elements: ", direction)
+		}
+
+		value, err := strconv.Atoi(directionAndValue[1])
+
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		switch directionAndValue[0] {
+		case "forward":
+			position.x += int64(value)
+		case "down":
+			position.y += int64(value)
+		case "up":
+			position.y -= int64(value)
+		}
+	}
+
+	return position.x * position.y
+}
diff --git a/d2/d2_test.go b/d2/d2_test.go
new file mode 100644
index 0000000..2342fce
--- /dev/null
+++ b/d2/d2_test.go
@@ -0,0 +1,20 @@
+package d2
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestD2(t *testing.T) {
+
+	input := `
+forward 5
+down 5
+forward 8
+up 3
+down 8
+forward 2`
+
+	assert.EqualValues(t, 150, D2(input))
+}
diff --git a/main.go b/main.go
index ede3869..0fd0c68 100644
--- a/main.go
+++ b/main.go
@@ -8,6 +8,7 @@ import (
 
 	"github.com/fotonmoton/aoc2021/client"
 	"github.com/fotonmoton/aoc2021/d1"
+	"github.com/fotonmoton/aoc2021/d2"
 )
 
 func main() {
@@ -18,4 +19,5 @@ func main() {
 	client := client.NewClient(strings.TrimSpace(session))
 
 	fmt.Printf("day1: %v\n", d1.D1(string(client.Day(1))))
+	fmt.Printf("day2: %v\n", d2.D2(string(client.Day(2))))
 }