adds day 2021\18 chaos

2021/18/input.txt

@@ -0,0 +1,100 @@
+[[6,[[9,4],[5,1]]],[[[6,5],[9,4]],2]]
+[[7,3],[[3,[5,5]],8]]
+[8,[[5,0],[[0,2],3]]]
+[[[8,7],[[2,0],[7,5]]],1]
+[[[2,[6,1]],[7,[6,1]]],[[7,3],1]]
+[[2,[9,[0,0]]],[[[9,7],1],0]]
+[[[[8,4],[2,3]],[[6,4],4]],0]
+[[[1,3],1],[[3,8],[[2,3],[9,5]]]]
+[[7,[5,9]],[[7,[9,1]],[3,[9,6]]]]
+[[[5,3],5],[[[8,8],[5,6]],[6,5]]]
+[3,[[4,1],3]]
+[[[5,[2,0]],[[9,5],[9,2]]],[[[1,7],[6,9]],[[6,3],[8,6]]]]
+[[[[9,3],[2,4]],[6,9]],[[[9,7],1],[[1,9],[2,9]]]]
+[3,[[6,1],8]]
+[[[[8,8],8],[[3,9],[9,3]]],[[8,8],[[7,1],[6,5]]]]
+[[[8,9],[[2,7],6]],[[[2,9],[8,4]],[1,6]]]
+[[4,[[4,4],0]],[[8,[1,8]],[9,[7,3]]]]
+[[[[3,0],[7,2]],[[9,5],[9,5]]],[5,[0,[5,7]]]]
+[5,[1,[[4,0],[8,5]]]]
+[[0,0],[[[9,8],1],[[5,2],[4,6]]]]
+[[5,8],[6,[[5,2],1]]]
+[[1,[[1,4],8]],8]
+[[[[1,7],[7,1]],[4,[8,0]]],0]
+[[[[5,9],0],[0,8]],[2,[[6,2],2]]]
+[2,[4,3]]
+[[[[4,0],[2,2]],7],[[8,7],[[8,1],1]]]
+[[[[6,0],[1,6]],[2,[6,2]]],[[9,6],[7,[8,2]]]]
+[[3,5],[[9,[4,0]],[[6,5],[1,0]]]]
+[[[[6,0],7],[8,[0,1]]],[[7,6],[[7,1],[9,6]]]]
+[[3,[[6,4],4]],[0,[[3,5],[8,6]]]]
+[[8,[[1,8],0]],[1,[[0,1],[6,2]]]]
+[[6,[5,[5,4]]],9]
+[[[[0,7],3],[[7,7],[1,2]]],[8,[2,1]]]
+[[[7,[1,4]],[5,[9,8]]],[1,8]]
+[[[0,7],[[3,6],[2,4]]],[[7,4],1]]
+[[[5,[8,2]],[[4,9],[5,3]]],4]
+[[5,[[3,3],0]],8]
+[7,[2,1]]
+[[3,8],[[[5,3],8],[[3,4],6]]]
+[[[2,[0,9]],[0,5]],0]
+[[6,[7,6]],[[[2,6],2],[[8,9],5]]]
+[[[0,0],[[1,9],[0,6]]],[[5,[8,8]],[[6,9],[3,7]]]]
+[[[[4,6],[8,4]],[2,[3,8]]],[8,0]]
+[[0,0],[2,[[6,2],6]]]
+[[[6,0],3],8]
+[[[[6,1],[4,8]],[2,[3,0]]],7]
+[[[0,[1,8]],[[8,1],6]],3]
+[2,[0,2]]
+[[[[9,6],8],[[1,9],[7,8]]],[[[0,6],[8,8]],[6,[2,3]]]]
+[[0,[6,[7,4]]],[[[0,9],[2,3]],[[8,8],0]]]
+[[[0,1],[7,[4,9]]],[[3,9],8]]
+[[[1,9],7],[[0,5],[5,[7,9]]]]
+[[[9,[2,5]],2],[7,[1,[7,7]]]]
+[[[[0,4],[7,3]],2],5]
+[[8,[7,4]],[[[8,2],[7,3]],[1,[7,8]]]]
+[[[0,4],[[3,7],9]],6]
+[[5,[[9,2],[7,0]]],[[8,2],[[1,4],9]]]
+[2,[[[9,6],9],[2,3]]]
+[[5,[[3,5],[3,8]]],[4,[2,9]]]
+[[[5,2],[4,[4,1]]],[[[1,0],[8,7]],[[8,7],8]]]
+[[4,[4,[0,9]]],[[1,8],4]]
+[[[3,[4,0]],[[8,8],[1,6]]],[[4,0],[1,2]]]
+[[[1,[1,8]],2],[[6,2],[9,[8,5]]]]
+[9,[[[8,8],[8,3]],[3,[1,3]]]]
+[[[2,[4,5]],[4,1]],[1,[[8,6],[1,5]]]]
+[[0,[5,[7,6]]],[[8,6],[[9,9],1]]]
+[[[5,[5,2]],2],[[[1,4],[3,7]],[4,3]]]
+[[5,[[9,8],0]],[7,[[0,8],[7,8]]]]
+[[[[8,0],6],[2,1]],[[[6,3],[3,1]],[[7,6],[7,2]]]]
+[[[3,3],6],[2,[[8,4],5]]]
+[[[6,[5,3]],[[6,4],3]],[[[4,8],0],[[0,6],[1,4]]]]
+[[[3,[6,4]],2],[[[8,8],4],[[8,6],6]]]
+[[[[6,9],1],[3,8]],[[5,[4,6]],2]]
+[[5,6],3]
+[[[5,[8,6]],[[4,2],[1,1]]],[[[0,7],[6,3]],[9,[7,7]]]]
+[[7,[[4,0],6]],[[4,[6,4]],8]]
+[[5,[[2,0],[9,4]]],[[[4,6],1],[[2,8],[8,5]]]]
+[[[[3,5],[0,4]],[[5,0],3]],[[1,[8,9]],7]]
+[[[[6,6],6],[[6,6],[4,3]]],0]
+[[5,[2,5]],[6,[[7,8],2]]]
+[[[7,[5,5]],[[7,4],[6,7]]],0]
+[[[3,3],3],[[1,9],[0,[9,2]]]]
+[[9,[4,1]],[6,[2,[9,6]]]]
+[[4,7],[9,[3,0]]]
+[[[8,2],[[9,8],[4,2]]],[[2,[3,7]],[7,[3,1]]]]
+[[[[1,8],2],[0,[6,5]]],[[[2,7],[8,6]],[[8,9],[8,5]]]]
+[[[7,[2,9]],[9,0]],5]
+[[5,[2,[1,5]]],[0,7]]
+[4,[[0,[0,3]],[[0,5],[9,0]]]]
+[0,[[4,4],[[8,4],[3,8]]]]
+[[[[4,9],0],[[4,4],9]],[[[6,1],[8,9]],[7,[2,3]]]]
+[[[[4,2],[7,4]],0],[[5,[0,6]],[[0,5],4]]]
+[[[1,0],8],[[[2,8],[2,9]],3]]
+[[6,[1,[9,9]]],[2,2]]
+[[[8,[6,7]],[6,[6,6]]],[[[2,3],5],0]]
+[[[7,[6,9]],[[7,8],[2,8]]],[[4,[5,1]],5]]
+[[[[6,3],[1,4]],7],[[9,1],[3,1]]]
+[5,[[8,5],[[7,5],4]]]
+[[4,[[4,0],0]],[6,[1,1]]]
+[[[5,[9,2]],[9,0]],[[5,[5,7]],4]]

2021/18/main.go

@@ -0,0 +1,294 @@
+package main
+
+import (
+	"fmt"
+	"math"
+	"strings"
+
+	"github.com/jdrst/adventofgo/util"
+)
+
+type sfnum struct {
+	parent, left, right *sfnum
+	first, second       *int
+}
+
+func main() {
+	fmt.Printf("First part: %v\n", partOne(util.ReadFile("input.txt")))
+	fmt.Printf("Second part: %v\n", partTwo(util.ReadFile("input.txt")))
+}
+
+func partOne(file util.File) int {
+	lines := file.AsLines()
+
+	for i := 0; i < len(lines)-1; i++ {
+		left := toSfnum(string(lines[i]))
+		right := toSfnum(string(lines[i+1]))
+
+		newLeft := &sfnum{left: left, right: right}
+		newLeft.left.parent = newLeft
+		newLeft.right.parent = newLeft
+		newLeft.reduce()
+		lines[i+1] = util.Line(newLeft.String())
+	}
+
+	last := toSfnum(string(lines[len(lines)-1]))
+	last.reduce()
+	return *last.magnitude()
+}
+
+func partTwo(file util.File) int {
+	lines := file.AsLines()
+
+	max := math.MinInt
+	for i := 0; i < len(lines); i++ {
+		for j := 0; j < len(lines); j++ {
+			if j == i {
+				continue
+			}
+			left := toSfnum(string(lines[i]))
+			right := toSfnum(string(lines[j]))
+			result := &sfnum{left: left, right: right}
+			result.left.parent = result
+			result.right.parent = result
+			result.reduce()
+			mag := result.magnitude()
+			if *mag > max {
+				max = *mag
+			}
+		}
+	}
+	for i := 0; i < len(lines); i++ {
+		for j := 0; j < len(lines); j++ {
+			if j == i {
+				continue
+			}
+			left := toSfnum(string(lines[i]))
+			right := toSfnum(string(lines[j]))
+			result := &sfnum{left: right, right: left}
+			result.left.parent = result
+			result.right.parent = result
+			result.reduce()
+			mag := result.magnitude()
+			if *mag > max {
+				max = *mag
+			}
+		}
+	}
+	return max
+}
+
+func (num *sfnum) magnitude() *int {
+	if num.left != nil {
+		num.first = num.left.magnitude()
+	}
+	if num.right != nil {
+		num.second = num.right.magnitude()
+	}
+	res := *num.first*3 + *num.second*2
+	return &res
+}
+
+func (num *sfnum) explode() {
+	// fmt.Printf("exploding [%v,%v]\n", *num.first, *num.second)
+	left, isLeft := findRegularLeft(num)
+	if left != nil {
+		if isLeft {
+			new := *left.first + *num.first
+			left.first = &new
+		} else {
+			new := *left.second + *num.first
+			left.second = &new
+		}
+	}
+	right, isLeft := findRegularRight(num)
+	if right != nil {
+		if isLeft {
+			new := *right.first + *num.second
+			right.first = &new
+		} else {
+			new := *right.second + *num.second
+			right.second = &new
+		}
+	}
+	null := 0
+	if num.parent.left == num {
+		num.parent.first = &null
+		num.parent.left = nil
+	}
+	if num.parent.right == num {
+		num.parent.second = &null
+		num.parent.right = nil
+	}
+}
+
+func (num *sfnum) split(left bool) {
+	split := func(from int) *sfnum {
+		newLeft := from / 2
+		newRight := from / 2
+		if from%2 == 1 {
+			newRight++
+		}
+		return &sfnum{first: &newLeft, second: &newRight, parent: num}
+	}
+	if left {
+		// fmt.Printf("splitting [%v,]\n", *num.first)
+		num.left = split(*num.first)
+		num.first = nil
+	} else {
+		// fmt.Printf("splitting [,%v]\n", *num.second)
+		num.right = split(*num.second)
+		num.second = nil
+	}
+}
+
+func (num *sfnum) reduce() {
+	noResult := true
+explode:
+	for noResult {
+		// fmt.Println(num)
+		noResult = num.explodeRecursive(0)
+	}
+	noResult = true
+	for noResult {
+		// fmt.Println(num)
+		noResult = num.splitRecursive()
+		if noResult {
+			goto explode
+		}
+	}
+}
+
+func (num *sfnum) explodeRecursive(depth int) bool {
+	res := false
+	if depth > 3 {
+		num.explode()
+		return true
+	}
+	if num.left != nil {
+		res = num.left.explodeRecursive(depth + 1)
+	}
+	if !res && num.right != nil {
+		res = num.right.explodeRecursive(depth + 1)
+	}
+	return res
+}
+
+func (num *sfnum) splitRecursive() bool {
+	res := false
+	if num.left != nil {
+		res = num.left.splitRecursive()
+	}
+	if !res && num.first != nil && *num.first > 9 {
+		num.split(true)
+		return true
+	}
+	if !res && num.right != nil {
+		res = num.right.splitRecursive()
+	}
+	if !res && num.second != nil && *num.second > 9 {
+		num.split(false)
+		return true
+	}
+	return res
+}
+
+func findRegularLeft(num *sfnum) (res *sfnum, isFirst bool) {
+	if num.parent == nil {
+		return nil, true
+	}
+	if num.parent.first != nil {
+		return num.parent, true
+	}
+	if num.parent.left != num {
+		res := findRightMost(num.parent.left)
+		return res, false
+	}
+	return findRegularLeft(num.parent)
+}
+
+func findRegularRight(num *sfnum) (res *sfnum, isFirst bool) {
+	if num.parent == nil {
+		return nil, false
+	}
+	if num.parent.second != nil {
+		return num.parent, false
+	}
+	if num.parent.right != num {
+		res := findLeftMost(num.parent.right)
+		return res, true
+	}
+	return findRegularRight(num.parent)
+}
+
+func findLeftMost(num *sfnum) *sfnum {
+	if num.left != nil {
+		return findLeftMost(num.left)
+	}
+	if num.first != nil {
+		return num
+	}
+	return nil
+}
+
+func findRightMost(num *sfnum) *sfnum {
+	if num.right != nil {
+		return findRightMost(num.right)
+	}
+	if num.second != nil {
+		return num
+	}
+	return nil
+}
+
+func toSfnum(s string) *sfnum {
+	num := &sfnum{}
+	isLeft := true
+	for _, c := range s[1 : len(s)-1] {
+		switch c {
+		case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			if isLeft {
+				fst := int(c - '0')
+				num.first = &fst
+			} else {
+				snd := int(c - '0')
+				num.second = &snd
+				isLeft = true
+			}
+		case ',':
+			isLeft = false
+		case '[':
+			child := &sfnum{parent: num}
+			if isLeft {
+				num.left = child
+			} else {
+				num.right = child
+				isLeft = true
+			}
+			num = child
+		case ']':
+			num = num.parent
+		}
+	}
+	return num
+}
+
+func (num *sfnum) String() string {
+	sb := strings.Builder{}
+	sb.WriteRune('[')
+	if num.left != nil {
+		sb.WriteString(fmt.Sprint(num.left))
+	}
+	if num.first != nil {
+		sb.WriteString(fmt.Sprint(*num.first))
+	}
+	sb.WriteRune(',')
+	if num.right != nil {
+		sb.WriteString(fmt.Sprint(num.right))
+	}
+	if num.second != nil {
+		sb.WriteString(fmt.Sprint(*num.second))
+	}
+	sb.WriteRune(']')
+	return sb.String()
+}