AoC Day 18, Part 1 (Solved)

2023/18/code.go

@@ -0,0 +1,132 @@
+package main
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/jpillora/puzzler/harness/aoc"
+)
+
+func main() {
+	aoc.Harness(run)
+}
+
+// on code change, run will be executed 4 times:
+// 1. with: false (part1), and example input
+// 2. with: true (part2), and example input
+// 3. with: false (part1), and user input
+// 4. with: true (part2), and user input
+// the return value of each run is printed to stdout
+
+func run(part2 bool, input string) any {
+	// when you're ready to do part 2, remove this "not implemented" block
+	if part2 {
+		// More complex
+		return "not implemented"
+	}
+	// solve part 1 here
+
+	// Get max dimensions (sumR + sumD)
+
+	// or just make a big ass grid
+
+	maxV := 1200
+	maxH := 1200
+
+	grid := make([][]string, 0)
+	for v := 0; v < maxV; v++ {
+		gridLine := make([]string, 0)
+		for h := 0; h < maxH; h++ {
+			gridLine = append(gridLine, ".")
+		}
+		grid = append(grid, gridLine)
+	}
+
+	v := maxV / 2
+	h := maxH / 2
+
+	// Dig out trench
+	for _, l := range strings.Split(input, "\n") {
+		if l == "" {
+			continue
+		}
+
+		spl := strings.Split(l, " ")
+
+		order := spl[0]
+		dist, _ := strconv.Atoi(spl[1])
+		colour := spl[2]
+
+		for i := 0; i < dist; i++ {
+			if order == "R" {
+				h += 1
+			} else if order == "L" {
+				h -= 1
+			} else if order == "U" {
+				v -= 1
+			} else if order == "D" {
+				v += 1
+			} else {
+				panic("bad direction")
+			}
+			grid[v][h] = colour
+		}
+	}
+
+	// Fill out outside
+	outside := [][]int{{0, 0}}
+	for len(outside) > 0 {
+		o := outside[0]
+		outside = outside[1:]
+
+		if grid[o[0]][o[1]] == "." {
+			grid[o[0]][o[1]] = " "
+
+			v = o[0]
+			h = o[1]
+
+			if v > 0 {
+				outside = append(outside, []int{v - 1, h})
+			}
+
+			if h > 0 {
+				outside = append(outside, []int{v, h - 1})
+			}
+
+			if v < len(grid)-1 {
+				outside = append(outside, []int{v + 1, h})
+			}
+
+			if h < len(grid[0])-1 {
+				outside = append(outside, []int{v, h + 1})
+			}
+		}
+	}
+
+	// Finally count fill-in
+	digout := 0
+	for v := range grid {
+		for h := range grid {
+			if grid[v][h] != " " {
+				digout += 1
+			}
+		}
+	}
+
+	print := false
+	if print {
+		for v := range grid {
+			for h := range grid[v] {
+				if len(grid[v][h]) == 1 {
+					fmt.Print(grid[v][h])
+				} else {
+					fmt.Print("#")
+				}
+			}
+			fmt.Println()
+		}
+	}
+
+	return digout
+}