From e4dc5c10344a5e4ba796810f043f548398ed7bff Mon Sep 17 00:00:00 2001
From: Karl Spickermann <karliosos65@googlemail.com>
Date: Sat, 18 Dec 2021 19:07:09 +0100
Subject: [PATCH] This is Bullshit

---
 src/day18/day18.go              | 126 ++++++++++++++++++++++++++++++++
 src/day18/day18TestAddition.txt |   2 +
 2 files changed, 128 insertions(+)
 create mode 100644 src/day18/day18.go
 create mode 100644 src/day18/day18TestAddition.txt

diff --git a/src/day18/day18.go b/src/day18/day18.go
new file mode 100644
index 0000000..33efbe2
--- /dev/null
+++ b/src/day18/day18.go
@@ -0,0 +1,126 @@
+package main
+
+import (
+	"AOC2021/src/helper"
+	"fmt"
+	"os"
+)
+
+type snailNumber struct {
+	pair   [2]*snailNumber
+	val    int
+	nested int
+}
+
+func main() {
+	args := os.Args[1:]
+	input, err := helper.GetInput(args[0])
+	if err != nil {
+		fmt.Println(err)
+	}
+	var snailNumberArray []snailNumber
+	for _, row := range input {
+		number, _ := parseSnailNumber(row[1:], 0)
+		snailNumberArray = append(snailNumberArray, number)
+	}
+	fmt.Println(addSnailNumberStrings(input[0], input[1]))
+	fmt.Println(checkExplode("[[[[[9,8],1],2],3],4]"))
+	fmt.Println(checkExplode("[7,[6,[5,[4,[3,2]]]]]"))
+	fmt.Println(checkExplode("[[6,[5,[4,[3,2]]]],1]"))
+
+}
+
+func addSnailNumberStrings(left string, right string) string {
+	return "[" + left + "," + right + "]"
+}
+
+func checkExplode(snailNumberString string) (string, bool) {
+	index := 0
+	openBracketCounter := 0
+	for index < len(snailNumberString) {
+		char := snailNumberString[index]
+		index++
+		if char == '[' {
+			openBracketCounter++
+		}
+		if char == ']' {
+			openBracketCounter--
+		}
+		if runeIsNumber(rune(char)) && openBracketCounter >= 5 {
+			return explode(snailNumberString, index), true
+		}
+	}
+	return snailNumberString, false
+}
+
+func explode(snailNumberString string, location int) string {
+	returnString := snailNumberString[:location-2] + snailNumberString[location+3:]
+	addedLeft := false
+	positionLeft := location - 2
+	index := positionLeft - 1
+	for !addedLeft {
+		if returnString[index] == ',' {
+			tmpRuneArray := []rune(returnString)
+			tmpInt := snailNumberString[location-1] + returnString[index-1] - '0'
+			tmpRuneArray[index-1] = rune(tmpInt)
+			returnString = string(tmpRuneArray)
+			addedLeft = true
+			if positionLeft-1 == index {
+				positionLeft = index - 1
+			}
+		}
+		index--
+		if index == 0 {
+			returnString = returnString[:positionLeft] + string(rune(48)) + returnString[positionLeft:]
+			addedLeft = true
+		}
+	}
+	addedRight := false
+	positionRight := positionLeft + 2
+	index = positionLeft + 1
+	for !addedRight {
+		if returnString[index] == ',' {
+			tmpRuneArray := []rune(returnString)
+			tmpInt := snailNumberString[location+1] + returnString[index+1] - '0'
+			tmpRuneArray[index+1] = rune(tmpInt)
+			returnString = string(tmpRuneArray)
+			addedRight = true
+		}
+		index++
+		if index == len(returnString) {
+			returnString = returnString[:positionRight] + "," + string(rune(48)) + returnString[positionRight:]
+			addedRight = true
+			index = location - 1
+		}
+	}
+	return returnString
+}
+
+func parseSnailNumber(input string, nested int) (number snailNumber, index int) {
+	index = 0
+	number.nested = nested
+	currentPairToFill := &number.pair[0]
+	for index < len(input) {
+		char := input[index]
+		index++
+		if char == '[' {
+			tmpNumber, tmpIndex := parseSnailNumber(input[index:], nested+1)
+			index += tmpIndex
+			*currentPairToFill = &tmpNumber
+		}
+		if char == ',' {
+			currentPairToFill = &number.pair[1]
+		}
+		if runeIsNumber(rune(char)) {
+			(*currentPairToFill) = &snailNumber{[2]*snailNumber{}, int(char - '0'), nested + 1}
+		}
+		if char == ']' {
+			return
+		}
+	}
+	return
+}
+
+func runeIsNumber(char rune) bool {
+	return char >= 48 && char <= 57
+}
diff --git a/src/day18/day18TestAddition.txt b/src/day18/day18TestAddition.txt
new file mode 100644
index 0000000..0c332be
--- /dev/null
+++ b/src/day18/day18TestAddition.txt
@@ -0,0 +1,2 @@
+[1,2]
+[[3,4],5]
\ No newline at end of file