From 27f270dd4ac2272e5af1947c647f6d3c63c23d20 Mon Sep 17 00:00:00 2001
From: Luke Else <mail@luke-else.co.uk>
Date: Tue, 14 Dec 2021 22:37:28 +0000
Subject: [PATCH] day 13b complete

took a while, output was a bit... broken :(
---
 day13/day 13b/main.go | 92 +++++++++++++++++++++++++++++++++++++++----
 day13/input           |  1 -
 2 files changed, 84 insertions(+), 9 deletions(-)

diff --git a/day13/day 13b/main.go b/day13/day 13b/main.go
index 2c4f028..d55e5dc 100644
--- a/day13/day 13b/main.go	
+++ b/day13/day 13b/main.go	
@@ -5,19 +5,100 @@ import (
 	"fmt"
 	"os"
 	"strconv"
+	"strings"
 )
 
 func main() {
 	content := returnContent("../input")
 	//content := returnContent("testInput")
 
+	sheet := make(map[Coordinate]bool)
+	//var answer string
+
+	for y := 0; y < 1000; y++ {
+		for x := 0; x < 1000; x++ {
+			sheet[Coordinate{X: x, Y: y}] = false
+		}
+	}
+
+	for _, line := range *content {
+
+		if strings.HasPrefix(line, "fold") {
+			//Fold instructions
+			instruction := strings.Split(line, "=")
+
+			if strings.Contains(instruction[0], "x") {
+				foldPoint, _ := strconv.Atoi(instruction[1])
+				sheet = FoldX(sheet, foldPoint)
+			}
+
+			if strings.Contains(instruction[0], "y") {
+				foldPoint, _ := strconv.Atoi(instruction[1])
+				sheet = FoldY(sheet, foldPoint)
+			}
+
+		} else if line != "" {
+			//mapping instructions
+			coordinates := strings.Split(line, ",")
+			x, _ := strconv.Atoi(coordinates[0])
+			y, _ := strconv.Atoi(coordinates[1])
+
+			sheet[Coordinate{X: x, Y: y}] = true
+
+		}
+	}
+
+	for y := 0; y < 8; y++ {
+		for x := 0; x < 200; x++ {
+			if sheet[Coordinate{X: x, Y: y}] {
+				fmt.Print("#")
+			} else {
+				fmt.Print(" ")
+			}
+		}
+		fmt.Print("\n")
+	}
+
 }
 
-func returnContent(path string) *[][]int {
+func FoldX(sheet map[Coordinate]bool, foldPoint int) (folded map[Coordinate]bool) {
+	folded = make(map[Coordinate]bool)
+	for mark := range sheet {
+		x := mark.X
+		if x > foldPoint {
+			//If the value is in the region that gets folded
+			x = 2*foldPoint - x
+		}
+
+		folded[Coordinate{X: x, Y: mark.Y}] = true
+	}
+	return
+}
+
+func FoldY(sheet map[Coordinate]bool, foldPoint int) (folded map[Coordinate]bool) {
+	folded = make(map[Coordinate]bool)
+	for mark := range sheet {
+		y := mark.X
+		if y > foldPoint {
+			//If the value is in the region that gets folded
+			y = 2*foldPoint - y
+		}
+
+		folded[Coordinate{X: mark.X, Y: y}] = true
+	}
+	return
+}
+
+type Coordinate struct {
+	X int
+	Y int
+}
+
+func returnContent(path string) *[]string {
 	//read file and return it as an array of integers
 
 	file, err := os.Open(path)
-	var content [][]int
+	var content []string
 
 	if err != nil {
 		fmt.Println("Unlucky, the file didn't open")
@@ -28,12 +109,7 @@ func returnContent(path string) *[][]int {
 	scanner := bufio.NewScanner(file)
 
 	for scanner.Scan() {
-		nums := []int{}
-		for _, char := range scanner.Text() {
-			num, _ := strconv.Atoi(string(char))
-			nums = append(nums, num)
-		}
-		content = append(content, nums)
+		content = append(content, scanner.Text())
 	}
 
 	return &content
diff --git a/day13/input b/day13/input
index ff66650..4efcf29 100644
--- a/day13/input
+++ b/day13/input
@@ -926,7 +926,6 @@
 723,325
 833,773
 211,415
-
 fold along x=655
 fold along y=447
 fold along x=327