AoC, Day 11, Parts 1 and 2 (Solved)

2023/11/code.go

@@ -0,0 +1,114 @@
+package main
+
+import (
+	"math"
+	"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 {
+
+	universe := make([][]rune, 0)
+	for _, l := range strings.Split(input, "\n") {
+		if l == "" {
+			continue
+		}
+		line := make([]rune, 0)
+		empty := true
+		for r := range strings.Split(l, "") {
+			if rune(l[r]) != '.' {
+				empty = false
+			}
+			line = append(line, rune(l[r]))
+		}
+
+		if empty {
+			for e := range line {
+				line[e] = '↕'
+			}
+		}
+		universe = append(universe, line)
+	}
+
+	// Now expand inner cols
+	for h := 0; h < len(universe[0]); h++ {
+		empty := true
+		for v := range universe {
+			if universe[v][h] != '.' && universe[v][h] != '↕' {
+				empty = false
+			}
+		}
+
+		if empty {
+			for v := range universe {
+				if universe[v][h] == '↕' {
+					universe[v][h] = '⥁'
+				} else {
+					universe[v][h] = '↔'
+				}
+			}
+		}
+	}
+
+	// when you're ready to do part 2, remove this "not implemented" block
+	factor := 1
+	if part2 {
+		factor = 1000000
+	} else {
+		// solve part 1 here
+		factor = 2
+	}
+
+	coords := make([][]int, 0)
+
+	vr := 0
+	for v := range universe {
+		if universe[v][0] == '↕' || universe[v][0] == '⥁' {
+			// expand else normal v
+			vr += factor
+		} else {
+			vr += 1
+		}
+
+		hr := 0
+		for h := range universe {
+			if universe[0][h] == '↔' || universe[0][h] == '⥁' {
+				hr += factor
+			} else {
+				hr += 1
+			}
+
+			if universe[v][h] == '#' {
+				coords = append(coords, []int{vr, hr})
+			}
+		}
+	}
+
+	sumHyp := 0
+	compared := 0
+	for c1 := 0; c1 < len(coords)-1; c1++ {
+		for c2 := c1 + 1; c2 < len(coords); c2++ {
+			// add rise and run?
+			lenv := int(math.Abs(float64(coords[c1][0] - coords[c2][0])))
+			lenh := int(math.Abs(float64(coords[c1][1] - coords[c2][1])))
+
+			// convert to int?
+			sumHyp += lenv + lenh
+
+			compared++
+		}
+	}
+
+	return sumHyp
+}