From 8e5dfcccd86154a635199f8444b33747fea4a4b9 Mon Sep 17 00:00:00 2001
From: Karl Spickermann <karliosos65@googlemail.com>
Date: Wed, 14 Dec 2022 01:18:45 +0100
Subject: [PATCH] Day 13

---
 day13/day13.go       | 155 +++++++++++++++++++++++++++++++++++++++----
 day13/testinputPart2 |  18 +++++
 2 files changed, 161 insertions(+), 12 deletions(-)
 create mode 100644 day13/testinputPart2

diff --git a/day13/day13.go b/day13/day13.go
index d3b88ab..30092ee 100644
--- a/day13/day13.go
+++ b/day13/day13.go
@@ -3,31 +3,151 @@ package main
 import (
 	"AOC2022/helper"
 	"fmt"
+	"reflect"
+	"sort"
 	"strconv"
 )
 
+type Packet struct {
+	value  int
+	values []Packet
+}
+
 func main() {
 	//args := os.Args[1:]
 	lines := helper.ReadTextFile("day13/input")
-	result := 0
-	index := 1
+	//part1(lines)
+	decodePacket2 := parse("[[2]]")
+	decodePacket6 := parse("[[6]]")
+	packets := []Packet{}
 	for i := 0; i < len(lines); i += 3 {
-		fmt.Println(lines[i])
-		fmt.Println(lines[i+1])
-		fmt.Println(comparePair(lines[i], lines[i+1]))
-		fmt.Println()
-		if comparePair(lines[i], lines[i+1]) == 0 {
-			result += index
+		packets = append(packets, parse(lines[i]))
+		packets = append(packets, parse(lines[i+1]))
+	}
+	packets = append(packets, decodePacket2)
+	packets = append(packets, decodePacket6)
+	sort.Slice(packets, func(i, j int) bool {
+		result := compare(packets[i], packets[j])
+		if result == 0 {
+			return true
+		}
+		return false
+	})
+	result := 1
+	for i, packet := range packets {
+		if reflect.DeepEqual(packet, decodePacket2) {
+			result *= i + 1
+			fmt.Println(2)
+			fmt.Println(i + 1)
+		}
+		if reflect.DeepEqual(packet, decodePacket6) {
+			result *= i + 1
+			fmt.Println(6)
+			fmt.Println(i + 1)
 		}
-
-		index++
 	}
 	fmt.Println(result)
 
 }
 
+func part1(lines []string) {
+	index := 1
+	result := 0
+	for i := 0; i < len(lines); i += 3 {
+		left := parse(lines[i][1 : len(lines[i])-1])
+		right := parse(lines[i+1][1 : len(lines[i+1])-1])
+		if compare(left, right) == 0 {
+			fmt.Println(index)
+			result += index
+		}
+		index++
+	}
+	fmt.Println(result)
+}
+
+// 2 same
+// 1 left higher
+// 0 left lower
+func compare(left, right Packet) int {
+	if left.value != -1 && right.value != -1 {
+		if left.value < right.value {
+			return 0
+		}
+		if left.value > right.value {
+			return 1
+		}
+		if left.value == right.value {
+			return 2
+		}
+	}
+	if left.value == -1 && right.value == -1 {
+		for i := 0; i < len(left.values); i++ {
+			if !(i < len(right.values)) {
+				return 1
+			}
+			result := compare(left.values[i], right.values[i])
+			if result == 0 {
+				return 0
+			}
+
+			if result == 1 {
+				return 1
+			}
+		}
+		if len(right.values) > len(left.values) {
+			return 0
+		}
+		return 2
+	}
+	if left.value != -1 {
+		result := compare(Packet{value: -1, values: []Packet{{value: left.value, values: []Packet{}}}}, right)
+		if result == 0 {
+			return 0
+		}
+
+		if result == 1 {
+			return 1
+		}
+
+	}
+	if right.value != -1 {
+		result := compare(left, Packet{value: -1, values: []Packet{{value: right.value, values: []Packet{}}}})
+
+		if result == 0 {
+			return 0
+		}
+
+		if result == 1 {
+			return 1
+		}
+	}
+	return 2
+}
+
+func parse(input string) Packet {
+	packet := Packet{-1, []Packet{}}
+	for i := 0; i < len(input); {
+		switch input[i] {
+		case '[':
+			endOfCurrentArray := getEndofCurrentArray(input[1:], i)
+			currentArray := input[i+1 : endOfCurrentArray]
+			packet.values = append(packet.values, parse(currentArray))
+			i = endOfCurrentArray + 1
+		case ',':
+			i++
+		default:
+			endOfCurrentValue := getEndofCurrentValue(input, i)
+			currentValue := helper.RemoveError(strconv.Atoi(input[i:endOfCurrentValue]))
+			packet.values = append(packet.values, Packet{value: currentValue, values: []Packet{}})
+			i = endOfCurrentValue + 1
+		}
+	}
+
+	return packet
+}
+
 // 0 Right Order
-//-1 Left Value to high
+//-1 Left Value too high
 //-2 Right had no values left
 func comparePair(left string, right string) int {
 	lefIndex := 0
@@ -92,7 +212,7 @@ func getNextElement(packet string, currentIndex int) (int, int) {
 	for index < len(packet) {
 		switch packet[index] {
 		case ',':
-			index++
+			return index, -4
 			break
 		case '[':
 			return index, -2
@@ -130,6 +250,17 @@ func getEndofCurrentArray(packet string, currentIndex int) int {
 	}
 }
 
+func getEndofCurrentValue(packet string, currentIndex int) int {
+	index := currentIndex
+	for index < len(packet) {
+		if packet[index] == ',' {
+			return index
+		}
+		index++
+	}
+	return index
+}
+
 func readElement(packet string, currentIndex int) (element, newIndex int) {
 	index := currentIndex
 	newIndex = 0
diff --git a/day13/testinputPart2 b/day13/testinputPart2
new file mode 100644
index 0000000..d188a15
--- /dev/null
+++ b/day13/testinputPart2
@@ -0,0 +1,18 @@
+[]
+[[]]
+[[[]]]
+[1,1,3,1,1]
+[1,1,5,1,1]
+[[1],[2,3,4]]
+[1,[2,[3,[4,[5,6,0]]]],8,9]
+[1,[2,[3,[4,[5,6,7]]]],8,9]
+[[1],4]
+[[2]]
+[3]
+[[4,4],4,4]
+[[4,4],4,4,4]
+[[6]]
+[7,7,7]
+[7,7,7,7]
+[[8,7,6]]
+[9]
\ No newline at end of file