Day 14

2022/day14.go

@@ -0,0 +1,181 @@
+package main
+
+import (
+	"aoc/util"
+	"bufio"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func showScan(scan [][]byte) {
+	for i := 0; i < len(scan); i++ {
+		for j := 0; j < len(scan[i]); j++ {
+			if scan[i][j] != 0 {
+				fmt.Printf("%c", scan[i][j])
+			} else {
+				fmt.Printf("%c", '.')
+			}
+		}
+		fmt.Println()
+	}
+}
+
+func Day14() error {
+	f, err := os.Open(filepath.Join(util.Cwd(), "day14.txt"))
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	var xbounds, ybounds [2]int
+	xbounds[0] = 5000
+	ybounds[0] = 5000
+	var walls [][][2]int
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		structure := scanner.Text()
+		transitions := strings.Split(structure, "->")
+
+		var trace [][2]int
+
+		for _, transition := range transitions {
+			coordsRaw := strings.Split(strings.TrimSpace(transition), ",")
+			coords := [2]int{util.MustInt(coordsRaw[0]), util.MustInt(coordsRaw[1])}
+
+			if coords[0] < xbounds[0] {
+				xbounds[0] = coords[0]
+			}
+
+			if coords[0] > xbounds[1] {
+				xbounds[1] = coords[0]
+			}
+
+			if coords[1] < ybounds[0] {
+				ybounds[0] = coords[1]
+			}
+
+			if coords[1] > ybounds[1] {
+				ybounds[1] = coords[1]
+			}
+			trace = append(trace, coords)
+		}
+
+		walls = append(walls, trace)
+	}
+
+	fmt.Println(xbounds, ybounds)
+
+	var (
+		width  = xbounds[1] - xbounds[0] + 3
+		height = ybounds[1] + 2
+	)
+
+	xbounds[0]--
+
+	scan := make([][]byte, height)
+	for i := range scan {
+		scan[i] = make([]byte, width)
+	}
+
+	fmt.Println(width, height)
+
+	for _, trace := range walls {
+		var prev = trace[0]
+		for i := 1; i < len(trace); i++ {
+			var increment [2]int
+
+			if trace[i][0] != prev[0] {
+				if trace[i][0] > prev[0] {
+					increment = [2]int{1, 0}
+				} else {
+					increment = [2]int{-1, 0}
+				}
+			} else {
+				if trace[i][1] > prev[1] {
+					increment = [2]int{0, 1}
+				} else {
+					increment = [2]int{0, -1}
+				}
+			}
+
+			for prev[0] != trace[i][0] || prev[1] != trace[i][1] {
+				scan[prev[1]][prev[0]-xbounds[0]] = '#'
+				prev[0] += increment[0]
+				prev[1] += increment[1]
+				scan[prev[1]][prev[0]-xbounds[0]] = '#'
+			}
+
+			prev = trace[i]
+		}
+	}
+
+	showScan(scan)
+
+	origin := [2]int{500 - xbounds[0], 0}
+
+	sandPos := [2]int{origin[0], origin[1]}
+	sand := 1
+	for sandPos[1] < ybounds[1] {
+		if scan[sandPos[1]+1][sandPos[0]] == 0 {
+			sandPos[1]++
+		} else if scan[sandPos[1]+1][sandPos[0]-1] == 0 {
+			sandPos[0]--
+			sandPos[1]++
+		} else if scan[sandPos[1]+1][sandPos[0]+1] == 0 {
+			sandPos[0]++
+			sandPos[1]++
+		} else {
+			scan[sandPos[1]][sandPos[0]] = 'o'
+			sandPos = [2]int{origin[0], origin[1]}
+			sand++
+		}
+	}
+
+	showScan(scan)
+
+	fmt.Println(sand - 1)
+
+	for {
+		if sandPos[0]+1 >= width {
+			for i := range scan {
+				scan[i] = append(scan[i], 0)
+			}
+			width++
+		} else if sandPos[0]-1 < 0 {
+			for i := range scan {
+				scan[i] = append([]byte{0}, scan[i]...)
+			}
+			origin[0]++
+			width++
+			sandPos[0]++
+		}
+
+		if sandPos[1] >= ybounds[1]+1 {
+			scan[sandPos[1]][sandPos[0]] = 'o'
+			sandPos = [2]int{origin[0], origin[1]}
+			sand++
+		} else if scan[sandPos[1]+1][sandPos[0]] == 0 {
+			sandPos[1]++
+		} else if scan[sandPos[1]+1][sandPos[0]-1] == 0 {
+			sandPos[0]--
+			sandPos[1]++
+		} else if scan[sandPos[1]+1][sandPos[0]+1] == 0 {
+			sandPos[0]++
+			sandPos[1]++
+		} else if sandPos[0] == origin[0] && sandPos[1] == origin[1] {
+			break
+		} else {
+			scan[sandPos[1]][sandPos[0]] = 'o'
+			sandPos = [2]int{origin[0], origin[1]}
+			sand++
+		}
+	}
+
+	showScan(scan)
+	fmt.Println(sand)
+
+	return nil
+}