day23, part2

day23/aLongWalk.go

@@ -2,24 +2,25 @@ package day23
 
 import (
 	"fmt"
-	"log"
 )
 
 // length of longest scenic route
 func Run() int {
 	fmt.Println("day 23")
+	max := 0
 	filename := "day23/input"
 	field := ReadField(filename)
-	finalPaths := RunDFSTingy(field)
-	// log.Println(finalPaths)
+	fmt.Println(field.SparseString())
+	// finalPaths := RunDFSTingy(field)
+	// // log.Println(finalPaths)
+
+	// for _, path := range finalPaths {
+	// 	if path.Visited.Cardinality() > max {
+	// 		log.Println("one path len is ", path.Visited.Cardinality())
+	// 		max = path.Visited.Cardinality()
+	// 	}
+	// }
 
-	max := 0
-	for _, path := range finalPaths {
-		if path.Visited.Cardinality() > max {
-			log.Println("one path len is ", path.Visited.Cardinality())
-			max = path.Visited.Cardinality()
-		}
-	}
 	return max
 }
 

day23/field.go

@@ -118,6 +118,36 @@ func (f *Field) String() (result string) {
 	return
 }
 
+func (f *Field) SparseString() (result string) {
+	result += "\n"
+	for row := 0; row <= f.MaxRow; row++ {
+		for col := 0; col <= f.MaxCol; col++ {
+			if row == 0 && col == f.StartCol {
+				result += "S"
+				continue
+			}
+			if row == f.MaxRow && col == f.EndCol {
+				result += "E"
+				continue
+			}
+
+			symb := f.Cells[Coord{Row: row, Col: col}]
+			if symb != Tree {
+				neighbors := f.NeighborsPart2(Coord{Row: row, Col: col})
+				if len(neighbors) > 2 {
+					result += "o"
+				} else {
+					result += "."
+				}
+			} else {
+				result += " "
+			}
+		}
+		result += "\n"
+	}
+	return
+}
+
 func ReadField(filename string) (result Field) {
 	bytes, err := os.ReadFile(filename)
 	if err != nil {

day23/graph.go

@@ -0,0 +1,248 @@
+package day23
+
+import (
+	"fmt"
+	"log"
+	"slices"
+
+	mapset "github.com/deckarep/golang-set/v2"
+)
+
+type Node struct {
+	index int
+	c Coord
+	name string
+}
+func (n Node)Name() string {
+	var r string
+	if n.index < 25 {
+		num := 'A' + n.index
+		r = string(rune(num))
+	} else {
+		num := 'a' + n.index - 25
+		r = string(rune(num))
+	}
+	return r
+}
+
+type Graph struct {
+	nodes map[Coord]Node
+	nodesByIndex []Node
+	edges [][]int // from, to, length. excluding from, including to
+}
+
+func MaxDist(from, to Node) (result int) {
+
+	return
+}
+
+func PrintFieldWithGraph(g Graph, f Field) (result string) {
+	result += "\n"
+	for row := 0; row <= f.MaxRow; row++ {
+		for col := 0; col <= f.MaxCol; col++ {
+			symb := f.Cells[Coord{Row: row, Col: col}]
+			if symb != Tree {
+				coord := Coord{Row: row, Col: col}
+				node, exists := g.nodes[coord]
+				if exists {
+					result += fmt.Sprint(node.Name())
+				} else {
+					result += "."
+				}
+			} else {
+				result += " "
+			}
+		}
+		result += "\n"
+	}
+	return
+}
+
+func CreateGraph(f Field) (g Graph) {
+	startCoord := Coord{Row: 0, Col: f.StartCol}
+	// directly below start
+	initialPath := PathEnd{
+		end: Coord{Row: 1, Col: f.StartCol}, visited: mapset.NewSet[Coord](),
+	}
+
+	g = Graph{
+		nodes: map[Coord]Node{
+			startCoord: Node{
+				index: 0,
+				c: startCoord,
+				name: "A",
+			},
+		},
+	}
+
+	const presumedNodeCount = 36
+	g.edges = make([][]int, presumedNodeCount)
+	for i := 0; i < presumedNodeCount; i++ {
+		g.edges[i] = make([]int, presumedNodeCount)
+	}
+
+	recursiveGraphStep(f, initialPath, &g, startCoord, 1, mapset.NewSet[Coord]())
+	g.edges[0][0] = 0
+
+	g.nodesByIndex = make([]Node, len(g.nodes))
+	for _, node := range g.nodes {
+		g.nodesByIndex[node.index] = node
+	}
+
+	return
+}
+
+func (g *Graph)Neighbors(node Node) (nodes []Node) {
+	index := node.index
+	for toIndex, len := range g.edges[index] {
+		if len > 0 {
+			nodes = append(nodes, g.nodesByIndex[toIndex])
+		}
+	}
+	return
+}
+
+var maxSoFar int = -1
+func CheckMaxSoFar(maybe int) {
+	if maybe > maxSoFar {
+		maxSoFar = maybe
+	}
+}
+
+func (g *Graph) DFSLenOnGraph(atNode Node, visited mapset.Set[int],
+	toNode Node, lenSoFar int) int {
+
+	if atNode == toNode {
+		CheckMaxSoFar(lenSoFar)
+		return lenSoFar
+	}
+	log.Printf("at %+v to %+v cur dist is %d.\t\t|max so far %d| \n", atNode, toNode, lenSoFar, maxSoFar)
+
+	neighbors := g.Neighbors(atNode)
+	toVisit := slices.DeleteFunc(neighbors, func(n Node) bool {
+		return visited.Contains(n.index)
+	})
+
+	if len(toVisit) == 0 {
+		return -1
+	}
+	max := -1
+
+	for _, nextNode := range toVisit {
+		newVisited := visited.Clone()
+		newVisited.Add(atNode.index)
+		dist := g.edges[atNode.index][nextNode.index]
+		maxFromNext := g.DFSLenOnGraph(nextNode, newVisited, toNode, lenSoFar + dist)
+		if maxFromNext > max {
+			max = maxFromNext
+		}
+	}
+
+	return max
+}
+
+// run dfs, remembering from which remembers from which node we go, which path already traversed
+func recursiveGraphStep(f Field, p PathEnd, g *Graph, goingFrom Coord, goingLen int, visitedPathPoints mapset.Set[Coord]) {
+	// log.Printf("entering coord %+v. from %+v with len %d\n", p.end, goingFrom, goingLen)
+
+	// if visitedPathPoints.Contains(p.end) {
+	// 	return
+	// }
+
+	neighbors := f.NeighborsPart2(p.end)
+
+	isCrossRoad := len(neighbors) > 2
+	if isCrossRoad {
+		log.Println("this should be crossroad ", p.end)
+	}
+	isStart := p.end == Coord{Row: 0, Col: f.StartCol}
+	isEnd := p.end == f.EndCoord()
+	if isEnd {
+		log.Println("this should be end ", p.end)
+	}
+
+	isNode := isCrossRoad || isStart || isEnd
+
+	continuedPaths := ExtendPath(p, f)
+
+	if !isNode {
+		// just recurse into next paths, from same node, with increased len
+		visitedPathPoints.Add(p.end)
+		for _, nextStep := range continuedPaths {
+			recursiveGraphStep(f, nextStep, g, goingFrom, goingLen+1, visitedPathPoints)
+		}
+	} else {
+		node, known := g.nodes[p.end]
+		// check if known, if not known - create
+		if !known {
+			node = Node{
+				c: p.end,
+				index: len(g.nodes),
+			}
+			node.name = node.Name()
+			g.nodes[p.end] = node
+			log.Printf("creating node %s %+v\n", node.Name(), node)
+		}
+		from := g.nodes[goingFrom]
+		log.Printf("from %s to %s\n", from.Name(), node.Name())
+		// and add vertices to currently traversed
+		if g.edges[node.index][from.index] == 0 {
+			g.edges[node.index][from.index] = goingLen
+			g.edges[from.index][node.index] = goingLen
+		} else {
+			knownEdge := g.edges[node.index][from.index]
+			if goingLen > knownEdge {
+				g.edges[node.index][from.index] = goingLen
+				g.edges[from.index][node.index] = goingLen
+			}
+		}
+		// NOTE ah, it's possible to have two edges between i and j
+		// but, i only need the longest one
+		// log.Printf("adding edges between %d & %d of len %d\n", node.index, from.index, goingLen)
+
+		// continue with new 'from' and len of 1
+		if !known {
+			for _, nextStep := range continuedPaths {
+				log.Printf("from %s should recurse to %+v", node.Name(), nextStep)
+				recursiveGraphStep(f, nextStep, g, p.end, 1, visitedPathPoints)
+			}
+		}
+	}
+
+	return
+}
+
+func GraphToMermaid(g Graph) (result string) {
+	result += "\nflowchart LR\n"
+	lines := mapset.NewSet[string]()
+	for _, node := range g.nodes {
+		for to, len := range g.edges[node.index] {
+			var toNode Node
+			for _, other := range g.nodes {
+				if other.index == to {
+					toNode = other
+				}
+			}
+			if len > 0 {
+				var fromName, toName string
+				if node.index < toNode.index {
+					fromName = node.Name()
+					toName = toNode.Name()
+				} else {
+					fromName = toNode.Name()
+					toName = node.Name()
+				}
+				line := fmt.Sprintf("\t%s---|length %d|%s\n", fromName, len, toName)
+				lines.Add(line)
+			}
+		}
+		// result += fmt.Sprintf("%s--|%d|%s\n", a ...any)
+	}
+
+	for line := range lines.Iter() {
+		result += line
+	}
+
+	return
+}
+

day23/graph_test.go

@@ -0,0 +1,101 @@
+package day23
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	mapset "github.com/deckarep/golang-set/v2"
+)
+
+func TestGraphCreate(t *testing.T) {
+	filename := "example2"
+	field := ReadField(filename)
+
+	fmt.Println(field.SparseString())
+
+	graph := CreateGraph(field)
+	t.Log(graph)
+}
+
+func TestPrintGraph(t *testing.T) {
+	filename := "example2"
+	field := ReadField(filename)
+
+	fmt.Println(field.SparseString())
+
+	graph := CreateGraph(field)
+	t.Log(PrintFieldWithGraph(graph, field))
+	t.Logf(">>>\n %+v\n", graph)
+
+}
+
+func TestPrintGraphInput(t *testing.T) {
+	filename := "input"
+	field := ReadField(filename)
+
+	fmt.Println(field.SparseString())
+
+	graph := CreateGraph(field)
+	t.Log(PrintFieldWithGraph(graph, field))
+	t.Logf(">>>\n %+v\n", graph)
+
+}
+
+func TestPrintMermaidGraphInput(t *testing.T) {
+	filename := "input"
+	field := ReadField(filename)
+
+	fmt.Println(field.SparseString())
+
+	graph := CreateGraph(field)
+	mmdContent := GraphToMermaid(graph)
+	t.Log(mmdContent)
+
+	fileBorder, err := os.Create(filename + ".mmd")
+	if err != nil {
+		panic(err)
+	}
+	defer func() {
+		if err := fileBorder.Close(); err != nil {
+			panic(err)
+		}
+	}()
+
+	fileBorder.WriteString(mmdContent)
+}
+
+func TestGraphMaxBetweenExample(t *testing.T) {
+	filename := "example"
+	field := ReadField(filename)
+	graph := CreateGraph(field)
+
+	t.Log(PrintFieldWithGraph(graph, field))
+
+
+	from := graph.nodes[Coord{Row: 0, Col: field.StartCol}]
+	to := graph.nodes[field.EndCoord()]
+
+	dist := graph.DFSLenOnGraph(from, mapset.NewSet[int](), to, 0)
+
+	t.Log(graph)
+	t.Logf("please dist %d", dist)
+
+}
+
+func TestGraphMaxBetweenInput(t *testing.T) {
+	filename := "input"
+	field := ReadField(filename)
+
+	graph := CreateGraph(field)
+
+	t.Log(PrintFieldWithGraph(graph, field))
+	from := graph.nodes[Coord{Row: 0, Col: field.StartCol}]
+	to := graph.nodes[field.EndCoord()]
+
+	dist := graph.DFSLenOnGraph(from, mapset.NewSet[int](), to, 0)
+
+	t.Log(graph)
+	t.Logf("please dist %d", dist)
+
+}

day23/input.mmd

@@ -0,0 +1,62 @@
+
+flowchart LR
+	M---|length 166|N
+	d---|length 62|h
+	H---|length 190|I
+	f---|length 136|h
+	j---|length 94|k
+	B---|length 152|L
+	I---|length 40|J
+	W---|length 56|X
+	E---|length 214|F
+	C---|length 60|K
+	V---|length 142|b
+	a---|length 110|b
+	I---|length 138|P
+	J---|length 184|K
+	Y---|length 146|a
+	c---|length 190|d
+	Q---|length 114|T
+	J---|length 240|O
+	C---|length 184|D
+	L---|length 172|M
+	Q---|length 140|R
+	Y---|length 464|k
+	O---|length 76|V
+	N---|length 102|O
+	K---|length 152|L
+	U---|length 80|c
+	V---|length 72|W
+	b---|length 202|j
+	A---|length 39|B
+	W---|length 236|a
+	P---|length 166|Q
+	e---|length 174|f
+	G---|length 186|R
+	T---|length 258|d
+	X---|length 142|Y
+	b---|length 128|c
+	F---|length 378|G
+	S---|length 108|T
+	N---|length 62|W
+	U---|length 110|V
+	a---|length 138|k
+	S---|length 234|e
+	d---|length 108|e
+	H---|length 166|Q
+	O---|length 158|P
+	M---|length 360|X
+	h---|length 184|i
+	B---|length 244|C
+	D---|length 96|J
+	D---|length 154|E
+	R---|length 118|S
+	E---|length 146|I
+	P---|length 128|U
+	T---|length 268|U
+	i---|length 198|j
+	G---|length 144|H
+	F---|length 102|H
+	f---|length 77|g
+	K---|length 266|N
+	c---|length 64|i

day23/notes.org

@@ -76,3 +76,50 @@ so 4,10 and 3,11 should be visited separately.
 6,17 is where they join and the point which should have second entry
 ** allright, ugh. my new solution is memory hogging.
 maybe i can draw the stuff and it will be several neat thingies
+* maybe new approach?
+make a graph. with vertices of Start, End and Crossroads.
+yes.
+let's create a graph representation.
+** so, from A to AG
+i think i can do this manually now
+** distances are
+39
+244
+184
+154
+214
+378
+144
+190
+40
+184
+152
+172
+166
+102
+158
+166
+140
+118
+108
+268
+110
+72
+56
+142
+146
+110
+128
+190
+108
+174
+77
+1
+** again?
+no, let's write code.
+** didn't count all the way
+2023/12/23 15:55:55 at {index:30 c:{Row:125 Col:137} name:f} to {index:31 c:{Row:140 Col:139} name:g} cur dist is 3997.		|max so far 6406|
+signal: interrupt
+FAIL	sunshine.industries/aoc2023/day23	380.499s
+
+tried more or less stable value, and interrupted

day23/willHelp.mmd

@@ -0,0 +1,72 @@
+flowchart LR
+    L---|length 152|K
+    L---|length 172|M
+    U---|length 268|T
+    U---|length 110|V
+    W---|length 72|V
+    W---|length 56|X
+    a---|length 146|Y
+    a---|length 110|b
+    f---|length 174|e
+    f---|length 77|g
+    f---|length 136|h
+    H---|length 144|G
+    H---|length 190|I
+    T---|length 108|S
+    T---|length 268|U
+    M---|length 172|L
+    M---|length 166|N
+    F---|length 214|E
+    F---|length 378|G
+    I---|length 190|H
+    I---|length 40|J
+    A---|length 2|A
+    A---|length 39|B
+    Q---|length 166|P
+    Q---|length 140|R
+    Y---|length 142|X
+    Y---|length 146|a
+    d---|length 190|c
+    d---|length 108|e
+    e---|length 108|d
+    e---|length 174|f
+    h---|length 136|f
+    h---|length 184|i
+    J---|length 40|I
+    J---|length 184|K
+    N---|length 166|M
+    N---|length 102|O
+    X---|length 56|W
+    X---|length 142|Y
+    j---|length 198|i
+    j---|length 94|k
+    B---|length 39|A
+    B---|length 244|C
+    G---|length 378|F
+    G---|length 144|H
+    P---|length 158|O
+    P---|length 166|Q
+    D---|length 184|C
+    D---|length 154|E
+    E---|length 154|D
+    E---|length 214|F
+    K---|length 184|J
+    K---|length 152|L
+    O---|length 102|N
+    O---|length 158|P
+    R---|length 140|Q
+    R---|length 118|S
+    S---|length 118|R
+    S---|length 108|T
+    V---|length 110|U
+    V---|length 72|W
+    c---|length 128|b
+    c---|length 190|d
+    C---|length 244|B
+    C---|length 184|D
+    k---|length 94|j
+    i---|length 184|h
+    i---|length 198|j
+    g---|length 77|f
+    b---|length 110|a
+    b---|length 128|c