2022 Day 9 Complete!

2022-12-09 09:03:12 -06:00
parent 30b00e68a4
commit f5270a396a
6 changed files with 2503 additions and 0 deletions
--- a/2022/day09/main.go
+++ b/2022/day09/main.go
@@ -0,0 +1,166 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"time"
+
+	h "git.bullercodeworks.com/brian/adventofcode/helpers"
+)
+
+var sleepTime = (time.Second / 5)
+
+var minx, miny, maxx, maxy int
+
+func main() {
+	inp := h.StdinToStringSlice()
+
+	watch := len(os.Args) > 1 && strings.HasPrefix(os.Args[1], "-w")
+	if watch {
+		if strings.Contains(os.Args[1], "=") {
+			pts := strings.Split(os.Args[1], "=")
+			sleepTime = (time.Second / time.Duration(h.Atoi(pts[1])))
+		}
+	}
+	simulate(inp, 10, watch)
+}
+
+func buildInstructions(inp []string) []byte {
+	var inst []byte
+	for i := range inp {
+		dir, count := inp[i][0], h.Atoi(inp[i][2:])
+		for j := 0; j < count; j++ {
+			inst = append(inst, dir)
+		}
+	}
+	return inst
+}
+
+func simulate(inp []string, knotCount int, watch bool) {
+	if watch {
+		fmt.Print(h.CLEAR_SCREEN)
+	}
+	visited := make(map[h.Coordinate]bool)
+	inst := buildInstructions(inp)
+	var knots []h.Coordinate
+	for i := 0; i < knotCount; i++ {
+		knots = append(knots, h.Coordinate{X: 0, Y: 0})
+	}
+	if watch {
+		fmt.Println("# Part 1")
+		printVisits(visited, knots)
+	}
+	for i, dir := range inst {
+		moveHead(dir, knots)
+		visited[knots[len(knots)-1]] = true
+		if watch {
+			time.Sleep(sleepTime)
+			fmt.Print(h.CLEAR_SCREEN)
+			fmt.Printf("# Part 1 (%d/%d)\n", i, len(inst))
+			printVisits(visited, knots)
+		}
+	}
+	if watch {
+		time.Sleep(sleepTime)
+		fmt.Print(h.CLEAR_SCREEN)
+	}
+	fmt.Println("# Part 1")
+	if watch {
+		printVisits(visited, knots)
+	}
+	fmt.Printf("Tail visited %d positions\n", len(visited))
+}
+
+func moveHead(dir byte, knots []h.Coordinate) {
+	prevKnots := make([]h.Coordinate, len(knots))
+	copy(prevKnots, knots)
+	switch dir {
+	case 'U':
+		knots[0] = knots[0].North()
+	case 'R':
+		knots[0] = knots[0].East()
+	case 'D':
+		knots[0] = knots[0].South()
+	case 'L':
+		knots[0] = knots[0].West()
+	}
+	if knots[0].X < minx {
+		minx = knots[0].X
+	}
+	if knots[0].X > maxx {
+		maxx = knots[0].X
+	}
+	if knots[0].Y < miny {
+		miny = knots[0].Y
+	}
+	if knots[0].Y > maxy {
+		maxy = knots[0].Y
+	}
+	for i := 1; i < len(knots); i++ {
+		// Go through all knots and check if any need to move
+		if !knots[i].Equals(knots[i-1]) && !knots[i].Adjacent(knots[i-1]) {
+			if knots[i].X == knots[i-1].X {
+				// Same column
+				if knots[i].Y < knots[i-1].Y {
+					knots[i].Y++
+				} else {
+					knots[i].Y--
+				}
+			} else if knots[i].Y == knots[i-1].Y {
+				// Save row
+				if knots[i].X < knots[i-1].X {
+					knots[i].X++
+				} else {
+					knots[i].X--
+				}
+			} else {
+				// Not in the same row or column
+				if knots[i].X < knots[i-1].X {
+					knots[i].X++
+				} else {
+					knots[i].X--
+				}
+				if knots[i].Y < knots[i-1].Y {
+					knots[i].Y++
+				} else {
+					knots[i].Y--
+				}
+			}
+		} else {
+			// If one knot didn't need to move, none behind it will
+			break
+		}
+	}
+}
+
+func printVisits(m map[h.Coordinate]bool, knots []h.Coordinate) {
+	for y := miny; y <= maxy; y++ {
+		for x := minx; x <= maxx; x++ {
+			var isKnot bool
+			for i := range knots {
+				if knots[i].X == x && knots[i].Y == y {
+					isKnot = true
+					var bt byte
+					if i == 0 {
+						bt = 'H'
+					} else {
+						bt = '0' + byte(i)
+					}
+					fmt.Print(string(bt))
+					break
+				}
+			}
+			if !isKnot {
+				if v, ok := m[h.Coordinate{X: x, Y: y}]; ok && v {
+					fmt.Print("#")
+				} else {
+					fmt.Print(".")
+				}
+			}
+		}
+		fmt.Println()
+	}
+	fmt.Printf("Bridge: %s\n", knots)
+	fmt.Println()
+}