2022 Day 23 Complete

2022-12-27 10:44:20 -06:00
parent 667c3a4dc9
commit cdc31b204b
17 changed files with 4631 additions and 1 deletions
--- a/2022/day23/main.go
+++ b/2022/day23/main.go
@@ -0,0 +1,201 @@
+package main
+
+import (
+	"fmt"
+	"math"
+	"sort"
+
+	h "git.bullercodeworks.com/brian/adventofcode/helpers"
+)
+
+func main() {
+	inp := h.StdinToStringSlice()
+	part1(inp)
+	part2(inp)
+}
+
+func part1(inp []string) {
+	field := plotElves(inp)
+	for i := 0; i < 10; i++ {
+		proposals := buildProposals(field, i)
+		for k, v := range proposals {
+			delete(field, v)
+			field[k] = true
+		}
+	}
+	fmt.Println("# Part 1")
+	fmt.Println("Empty Tiles:", countEmpties(field))
+}
+func part2(inp []string) {
+	field := plotElves(inp)
+	var lastHash string
+	for i := 0; i < 100000000; i++ {
+		proposals := buildProposals(field, i)
+		for k, v := range proposals {
+			delete(field, v)
+			field[k] = true
+		}
+		currHash := fieldHash(field)
+		if currHash == lastHash {
+			fmt.Println("# Part 2")
+			fmt.Println("Stable on round", i+1)
+			return
+		}
+		lastHash = currHash
+	}
+	fmt.Println("# Part 2")
+	fmt.Println("No solution found.")
+}
+func fieldHash(field map[h.Coordinate]bool) string {
+	var sorted []h.Coordinate
+	for k := range field {
+		sorted = append(sorted, k)
+	}
+	sort.Slice(sorted, func(i, j int) bool {
+		if sorted[i].X == sorted[j].X {
+			return sorted[i].Y > sorted[j].Y
+		}
+		return sorted[i].X > sorted[j].X
+	})
+	return fmt.Sprintf("%v", sorted)
+}
+
+func countEmpties(field map[h.Coordinate]bool) int {
+	maxX, minX := math.MinInt, math.MaxInt
+	maxY, minY := math.MinInt, math.MaxInt
+	for k := range field {
+		maxX = h.Max(maxX, k.X)
+		minX = h.Min(minX, k.X)
+		maxY = h.Max(maxY, k.Y)
+		minY = h.Min(minY, k.Y)
+	}
+	var ret int
+	for y := minY; y <= maxY; y++ {
+		for x := minX; x <= maxX; x++ {
+			if _, ok := field[h.Coordinate{X: x, Y: y}]; !ok {
+				ret++
+			}
+		}
+	}
+	return ret
+}
+func printField(field map[h.Coordinate]bool) {
+	maxX, minX := math.MinInt, 0
+	maxY, minY := math.MinInt, 0
+	for k := range field {
+		maxX = h.Max(maxX, k.X)
+		minX = h.Min(minX, k.X)
+		maxY = h.Max(maxY, k.Y)
+		minY = h.Min(minY, k.Y)
+	}
+	maxX = maxX + 2
+	maxY = maxY + 2
+	for y := minY; y <= maxY; y++ {
+		for x := minX; x <= maxX; x++ {
+			if _, ok := field[h.Coordinate{X: x, Y: y}]; ok {
+				fmt.Print("#")
+			} else {
+				fmt.Print(".")
+			}
+		}
+		fmt.Println()
+	}
+}
+func plotElves(inp []string) map[h.Coordinate]bool {
+	field := make(map[h.Coordinate]bool)
+	for y := range inp {
+		for x := range inp[y] {
+			if inp[y][x] == '#' {
+				field[h.Coordinate{X: x, Y: y}] = true
+			}
+		}
+	}
+	return field
+}
+func buildProposals(field map[h.Coordinate]bool, round int) map[h.Coordinate]h.Coordinate {
+	props := make(map[h.Coordinate]h.Coordinate)
+	var errProps []h.Coordinate
+	for k := range field {
+		var neighbors []h.Coordinate
+		for _, n := range k.GetAllNeighbors() {
+			if _, ok := field[n]; ok {
+				neighbors = append(neighbors, n)
+			}
+		}
+		if len(neighbors) == 0 {
+			continue
+		}
+		var hasNorth, hasEast, hasSouth, hasWest bool
+		for _, n := range neighbors {
+			if n.Y < k.Y {
+				hasNorth = true
+			}
+			if n.Y > k.Y {
+				hasSouth = true
+			}
+			if n.X < k.X {
+				hasWest = true
+			}
+			if n.X > k.X {
+				hasEast = true
+			}
+		}
+		addProp := func(c h.Coordinate) {
+			if _, ok := props[c]; ok {
+				errProps = append(errProps, c)
+			} else {
+				props[c] = k
+			}
+		}
+		testNorth := func(c h.Coordinate) bool {
+			if !hasNorth {
+				addProp(k.North())
+				return true
+			}
+			return false
+		}
+		testSouth := func(c h.Coordinate) bool {
+			if !hasSouth {
+				addProp(k.South())
+				return true
+			}
+			return false
+		}
+		testWest := func(c h.Coordinate) bool {
+			if !hasWest {
+				addProp(k.West())
+				return true
+			}
+			return false
+		}
+		testEast := func(c h.Coordinate) bool {
+			if !hasEast {
+				addProp(k.East())
+				return true
+			}
+			return false
+		}
+		findProposal := func(c h.Coordinate, tests ...func(h.Coordinate) bool) {
+			for i := range tests {
+				if tests[i](c) == true {
+					return
+				}
+			}
+		}
+		switch round % 4 {
+		case 0: // North First
+			findProposal(k, testNorth, testSouth, testWest, testEast)
+		case 1: // South First
+			findProposal(k, testSouth, testWest, testEast, testNorth)
+		case 2: // West First
+			findProposal(k, testWest, testEast, testNorth, testSouth)
+		case 3: // East First
+			findProposal(k, testEast, testNorth, testSouth, testWest)
+		}
+	}
+	// Now remove all conflicts
+	for i := range errProps {
+		delete(props, errProps[i])
+	}
+	return props
+}