2023 Day 11 Complete!

Added a todo file to track changes to my helpers that need
to be propagated through previous days/years

2023/day11/main.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"fmt"
+
+	h "git.bullercodeworks.com/brian/adventofcode/helpers"
+)
+
+func main() {
+	inp := h.StdinToStringSlice()
+	part1(inp)
+	fmt.Println()
+	part2(inp)
+}
+
+func part1(input []string) {
+	m := h.StringSliceToCoordByteMap(input)
+	for y := m.Height() - 1; y >= 0; y-- {
+		if !m.RowContains(y, '#') {
+			m.InsertRowAfter(y, '.')
+		}
+	}
+	for x := m.Width() - 1; x >= 0; x-- {
+		if !m.ColContains(x, '#') {
+			m.InsertColAfter(x, '.')
+		}
+	}
+	galaxies := m.FindAll('#')
+	var result int
+	for i := 0; i < len(galaxies); i++ {
+		for j := i + 1; j < len(galaxies); j++ {
+			result += galaxies[i].Distance(galaxies[j])
+		}
+	}
+	fmt.Println("# Part 1")
+	fmt.Println(result)
+}
+
+func part2(input []string) {
+	m := h.StringSliceToCoordByteMap(input)
+	expansion := 1000000
+
+	galaxies := m.FindAll('#')
+	for y := m.Height() - 1; y >= 0; y-- {
+		if !m.RowContains(y, '#') {
+			// For every '#' coordinate on a row _after_ y, add 1000000 to it's y coord
+			for i := 0; i < len(galaxies); i++ {
+				if galaxies[i].Y > y {
+					galaxies[i].Y += (expansion - 1)
+				}
+			}
+		}
+	}
+	for x := m.Width() - 1; x >= 0; x-- {
+		if !m.ColContains(x, '#') {
+			// For every '#' coordinate on a col _after_ x, add 1000000 to it's x coord
+			for i := 0; i < len(galaxies); i++ {
+				if galaxies[i].X > x {
+					galaxies[i].X += (expansion - 1)
+				}
+			}
+		}
+	}
+	var result int
+	for i := 0; i < len(galaxies); i++ {
+		for j := i + 1; j < len(galaxies); j++ {
+			result += galaxies[i].Distance(galaxies[j])
+		}
+	}
+	fmt.Println("# Part 2")
+	fmt.Println(result)
+}