Completed both parts of Day 11 puzzle

day10/day10.go

@@ -149,6 +149,7 @@ func FindDistance(lines []string) int {
 	}
 }
 
+// Point in Polygon algorithm
 func isInPolygon(row int, col int, lines [][]rune) bool {
 	count := 0
 	last := rune(0)

day11/day11.go

@@ -0,0 +1,221 @@
+package day11
+
+import (
+	"gitea.paas.celticinfo.fr/oabrivard/aoc2023/utils"
+)
+
+type Coord struct {
+	row int
+	col int
+}
+
+func expandUniverse(lines []string) [][]byte {
+	height := len(lines)
+	width := len(lines[0])
+	isRowEmpty := make([]bool, height)
+	isColEmpty := make([]bool, width)
+	emptyColCount := 0
+	emptyRowCount := 0
+
+	for row, l := range lines {
+		isRowEmpty[row] = true
+		emptyRowCount++
+		for _, c := range l {
+			if c == '#' {
+				isRowEmpty[row] = false
+				emptyRowCount--
+				break
+			}
+		}
+	}
+
+	for col := 0; col < width; col++ {
+		isColEmpty[col] = true
+		emptyColCount++
+		for row := 0; row < height; row++ {
+			if lines[row][col] == '#' {
+				isColEmpty[col] = false
+				emptyColCount--
+				break
+			}
+		}
+	}
+
+	result := make([][]byte, height+emptyRowCount)
+	destRow := 0
+
+	for row, l := range lines {
+		destCol := 0
+		result[destRow] = make([]byte, width+emptyColCount)
+		if isRowEmpty[row] {
+			result[destRow+1] = make([]byte, width+emptyColCount)
+			for destCol := range result[destRow] {
+				result[destRow][destCol] = '.'
+				result[destRow+1][destCol] = '.'
+			}
+			destRow += 2
+		} else {
+			for col := range l {
+				result[destRow][destCol] = lines[row][col]
+				destCol++
+				if isColEmpty[col] {
+					result[destRow][destCol] = lines[row][col]
+					destCol++
+				}
+			}
+			destRow++
+		}
+	}
+
+	return result
+}
+
+func getUniverseAsInt(universe [][]byte) ([][]int, []Coord) {
+	height := len(universe)
+	width := len(universe[0])
+	result := make([][]int, height)
+	coords := []Coord{}
+	galaxyID := 0
+
+	for row, line := range universe {
+		result[row] = make([]int, width)
+
+		for col, c := range line {
+			if c == '#' {
+				result[row][col] = galaxyID
+				coords = append(coords, Coord{row, col})
+				galaxyID++
+			} else {
+				result[row][col] = -1
+			}
+		}
+	}
+
+	return result, coords
+}
+
+func SumLengths(lines []string) int {
+	result := 0
+	_, coords := getUniverseAsInt(expandUniverse(lines))
+	galaxyCount := len(coords) - 1
+
+	for i := 0; i < galaxyCount; i++ {
+		for j := i + 1; j <= galaxyCount; j++ {
+			r1_c1 := coords[i]
+			r2_c2 := coords[j]
+			dist := 0
+			//dist2 := float64(0)
+			ab := r2_c2.row - r1_c1.row
+			if ab == 0 {
+				dist = utils.AbsInt(r2_c2.col - r1_c1.col)
+			} else {
+				bc := r2_c2.col - r1_c1.col
+				if bc == 0 {
+					dist = utils.AbsInt(r2_c2.row - r1_c1.row)
+				} else {
+					//dist2 = math.Sqrt(float64(utils.IntPow(ab, 2) + utils.IntPow(bc, 2)))        // euclidian distance
+					dist = utils.AbsInt(r2_c2.row-r1_c1.row) + utils.AbsInt(r2_c2.col-r1_c1.col) // Manhattan distance
+				}
+			}
+			result += dist
+			//fmt.Printf("(%d,%d) = %d, %v\n", i, j, dist, dist2)
+		}
+	}
+
+	return result
+}
+
+func getEmptyLines(lines []string) ([]bool, []bool) {
+	height := len(lines)
+	width := len(lines[0])
+	isRowEmpty := make([]bool, height)
+	isColEmpty := make([]bool, width)
+	emptyColCount := 0
+	emptyRowCount := 0
+
+	for row, l := range lines {
+		isRowEmpty[row] = true
+		emptyRowCount++
+		for _, c := range l {
+			if c == '#' {
+				isRowEmpty[row] = false
+				emptyRowCount--
+				break
+			}
+		}
+	}
+
+	for col := 0; col < width; col++ {
+		isColEmpty[col] = true
+		emptyColCount++
+		for row := 0; row < height; row++ {
+			if lines[row][col] == '#' {
+				isColEmpty[col] = false
+				emptyColCount--
+				break
+			}
+		}
+	}
+
+	return isRowEmpty, isColEmpty
+}
+
+func getCoords(universe []string, expansion int) []Coord {
+	coords := []Coord{}
+	galaxyID := 0
+	deltaRow := 0
+
+	isRowEmpty, isColEmpty := getEmptyLines(universe)
+
+	for row, line := range universe {
+		deltaCol := 0
+
+		if isRowEmpty[row] {
+			deltaRow += expansion
+		} else {
+			for col, c := range line {
+				if isColEmpty[col] {
+					deltaCol += expansion
+				} else {
+					if c == '#' {
+						coords = append(coords, Coord{row + deltaRow, col + deltaCol})
+						galaxyID++
+					}
+				}
+			}
+		}
+	}
+
+	return coords
+}
+
+func SumLengths2(lines []string, expansion int) int {
+	result := 0
+
+	coords := getCoords(lines, expansion)
+	galaxyCount := len(coords) - 1
+
+	for i := 0; i < galaxyCount; i++ {
+		for j := i + 1; j <= galaxyCount; j++ {
+			r1_c1 := coords[i]
+			r2_c2 := coords[j]
+			dist := 0
+			ab := r2_c2.row - r1_c1.row
+			if ab == 0 {
+				dist = utils.AbsInt(r2_c2.col - r1_c1.col)
+			} else {
+				bc := r2_c2.col - r1_c1.col
+				if bc == 0 {
+					dist = utils.AbsInt(r2_c2.row - r1_c1.row)
+				} else {
+					//dist2 = math.Sqrt(float64(utils.IntPow(ab, 2) + utils.IntPow(bc, 2)))        // euclidian distance
+					dist = utils.AbsInt(r2_c2.row-r1_c1.row) + utils.AbsInt(r2_c2.col-r1_c1.col) // Manhattan distance
+				}
+			}
+			result += dist
+			//fmt.Printf("(%d,%d) = %d, %v\n", i, j, dist, dist2)
+		}
+	}
+
+	return result
+}

day11/day11_test.go

@@ -0,0 +1,137 @@
+package day11
+
+import (
+	"fmt"
+	"testing"
+
+	"gitea.paas.celticinfo.fr/oabrivard/aoc2023/utils"
+)
+
+func TestExpandUniverse(t *testing.T) {
+	lines := []string{
+		"...#......",
+		".......#..",
+		"#.........",
+		"..........",
+		"......#...",
+		".#........",
+		".........#",
+		"..........",
+		".......#..",
+		"#...#.....",
+	}
+
+	result := expandUniverse(lines)
+
+	for _, l := range result {
+		fmt.Println(string(l))
+	}
+}
+
+func TestGetUniverseAsInt(t *testing.T) {
+	lines := []string{
+		"...#......",
+		".......#..",
+		"#.........",
+		"..........",
+		"......#...",
+		".#........",
+		".........#",
+		"..........",
+		".......#..",
+		"#...#.....",
+	}
+
+	result, coords := getUniverseAsInt(expandUniverse(lines))
+
+	fmt.Println("Number of galaxies:", len(coords))
+	for _, l := range result {
+		fmt.Println(l)
+	}
+}
+
+func TestSumLengths(t *testing.T) {
+	lines := []string{
+		"...#......",
+		".......#..",
+		"#.........",
+		"..........",
+		"......#...",
+		".#........",
+		".........#",
+		"..........",
+		".......#..",
+		"#...#.....",
+	}
+
+	result := SumLengths(lines)
+
+	if result != 374 {
+		t.Fatalf("expected 374, got %v", result)
+	}
+}
+
+func TestSumLengthsWithInput(t *testing.T) {
+	lines := utils.ReadLines("input.txt")
+
+	result := SumLengths(lines)
+
+	if result != 10077850 {
+		t.Fatalf("expected 10077850, got %v", result)
+	}
+}
+
+func TestSumLengths2(t *testing.T) {
+	lines := []string{
+		"...#......",
+		".......#..",
+		"#.........",
+		"..........",
+		"......#...",
+		".#........",
+		".........#",
+		"..........",
+		".......#..",
+		"#...#.....",
+	}
+
+	result := SumLengths2(lines, 1)
+
+	if result != 374 {
+		t.Fatalf("expected 374, got %v", result)
+	}
+
+	result = SumLengths2(lines, 10-1)
+
+	if result != 1030 {
+		t.Fatalf("expected 1030, got %v", result)
+	}
+
+	result = SumLengths2(lines, 100-1)
+
+	if result != 8410 {
+		t.Fatalf("expected 8410, got %v", result)
+	}
+
+	result = SumLengths2(lines, 1000000-1)
+
+	if result != 82000210 {
+		t.Fatalf("expected 82000210, got %v", result)
+	}
+}
+
+func TestSumLengths2WithInput(t *testing.T) {
+	lines := utils.ReadLines("input.txt")
+
+	result := SumLengths2(lines, 1)
+
+	if result != 10077850 {
+		t.Fatalf("expected 10077850, got %v", result)
+	}
+
+	result = SumLengths2(lines, 1000000-1)
+
+	if result != 504715068438 {
+		t.Fatalf("expected 504715068438, got %v", result)
+	}
+}

day11/input.txt

@@ -0,0 +1,140 @@
+...................#.....#...............#......................#......................#...................#...........................#....
+..................................................#................................................#..............#.........................
+......#.....#.................#..............................................................#..............................................
+......................................................#..................#.....#............................................................
+.....................................................................................#.....................................#................
+.#............................................................................................................#.............................
+..................#......................#............................#..............................................................#.....#
+......................................................................................................#.............#.......................
+..............................................#........#........................#................................................#..........
+.....#......................#......................................#.....#...................#..............................................
+.........................................................................................................#..................................
+......................#...............#............#........................................................................................
+..................................................................................................#.........................................
+..........#..................................................................................................#..............#..........#....
+....#...........................#..........................#..............................#.................................................
+........................................#............................................#.................................#.........#..........
+...................................................................#...........#..........................#.................................
+............................................................................................................................................
+............................................#...............................................................................................
+....................#.................................#................................................................................#....
+............................................................................................#...............................................
+............................................................................#........#.........................................#............
+...#...................#..........................#...............#......................................................#..................
+..............................#........#....................................................................................................
+................#................................................................................#.......................................#..
+......#..............................................................#...................#..................................................
+.#.........................................#..........#.........#..............#........................#............#......................
+............................................................................................................................................
+...........#...................................#...............................................................#.............#..............
+........................#........#........................................#..........#..................................................#...
+....#.....................................................#.................................#......................................#........
+...............................................................#...................................#....................#...................
+#.............................................................................#..................................#.............#............
+.............................#..........#.............................#...................................#.................................
+........................................................#...................................................................................
+.............#........................................................................................................#................#....
+...#.............................................#..................................#......#.....#..........................................
+................................#..............................#............................................................................
+...................#........................................................#...............................................................
+#..........................#.........................................................................#......#...........#...................
+.......#...........................#.....#..............#.................................................................................#.
+......................#.........................#...........................................................................................
+.....................................................................................................................#.......#......#.......
+.............................................................#....................#...............#.........................................
+.........#..................................................................................................................................
+...............................#............#....................#.....#...............#..................#.................................
+....#...........#.........#.........................#..............................................................#..................#.....
+.....................#.......................................................................#..............................................
+....................................................................................................#.......................................
+.....................................#..........#...............................#...........................#..........#..........#.......#.
+..........................................................................................#.................................................
+.#..........................................#.............................#.................................................................
+.................#...........#............................#.............................................#......................#............
+.........#...........................................................#..............#.......................................................
+..................................................................................................#.............#.......#...................
+.............................................................................#.......................................................#......
+......#.............#...........#..........#........#...........#...........................................#...............................
+.........................................................................#..................................................................
+........................................................#...........#...........#................................................#..........
+........................................#....................#..........................................#.............#.....................
+..........#...................#................................................................#..........................................#.
+..................#.................................................................................#..........#............................
+..........................................................................................#.................................................
+..........................................................#...............#.................................................................
+............#................................#......................#..........#.........................................#......#...........
+..#.......................#..................................................................................#.....#........................
+.................................................#...........................................#..............................................
+.........#........#..................#...........................#.....................#...............#.............................#......
+......................................................................#..........................#.....................#....................
+............................................................................................................................................
+........................#.....................................................................................#............#............#...
+..............#............................#.................................#......#.......................................................
+........#..........#........................................................................................................................
+............................#............................................#..........................#.......................................
+.......................................................#......#.........................................................#......#............
+.........................................................................................#.....#..................#.........................
+.......................#................#.......................................#............................#.......................#......
+............................................................................................................................................
+.........#.......................................................................................................................#..........
+...#..........#................................#...........#......#.....................................................................#...
+....................................................................................#.......................................................
+.............................#.....................................................................................#.....#..................
+...................................#.....................................................#.............#....................................
+.....#.............#................................#......................................................................................#
+.............#............................................#...................#.................#.....................#.....#......#........
+#...............................#.........#..........................................#......................................................
+.........................#...............................................#..................................................................
+.................................................................................#......................................................#...
+....#...........#..................................#......................................................#.................................
+..............................................#.....................#.......................#...........................#...................
+..............................#.........................#.............................................#.........#...........................
+.........................................#.....................................#...............................................#............
+.#.........#..................................................#..........................#...........................#......................
+............................................................................................................................................
+.........................................................................................................................................#..
+.......#..........................................#.......................#................................................#........#.......
+............................................................................................................................................
+.................#.........#.........................................#.........................#.....#......#...............................
+............................................#..........#......................#......#......................................................
+....................................#.............................................................................#.........................
+...........................................................#................................................................................
+.................................................................................#........#...............#..............................#..
+.......#...........#..............................#.........................................................................................
+..#...............................................................................................#.................#............#..........
+..............................................#..........#...............#..................................................................
+..................................#.....#.....................#.......................#...............#......#.............#................
+..........................#.................................................................................................................
+....................................................#..................................................................#....................
+...........................................................................#..............#.....#...........................................
+#...................#...........................................................#...........................................................
+...........................................#....................#....................................................................#......
+.......#.....#........................................#....................................................#................................
+..............................#...................................................................#.........................................
+.............................................................................#.......................................#......................
+.....................#....................................................................................................................#.
+.................................#....................................#........................#............................................
+......#...........................................#.........................................................................................
+...........................................#................................................................................#......#........
+..........#...............#.........................................................#.......................................................
+..................#...........................................................#.............................................................
+...............................................................#............................................#.......#.......................
+....#........#...................................................................................#..........................................
+......................#...................................................#...........#................#....................................
+........#..............................................#...................................#....................#...........................
+..................................................#.......................................................................#..........#......
+.#...................................#..........................................................................................#...........
+..........................................#........................................#...............#........................................
+..........................#.....#........................................................................................................#..
+..................#...........................#..........#...........................................................#......................
+...................................................#......................#...................................................#.............
+.........#................................................................................#.................................................
+..............#................................................................#............................................................
+...........................#.........#..............................#...................................#..........#....................#...
+..................................................................................................#.............................#...........
+..#..............................................#..........................................................................................
+.................#.....................................................#.................#..................................................
+.................................#.........#...................................................#......#.........#...........................
+..........#.........................................#.....#......................#..........................................................
+....................#..........................#................#...........................................................#......#........
+#........................#.............#..................................#.................................#...............................

start_day.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+if [[ -z "$1" ]]; then
+    echo "start_day.sh [day_number]"
+    exit 1
+fi
+
+if [ -d "./day$1" ]; then
+    echo "Directory ./day$1/ already exists"
+    exit 2
+fi
+
+mkdir "./day$1"
+echo "package day$1" > "./day$1/day$1.go"
+echo "package day$1" > "./day$1/day$1_test.go"
+touch "./day$1/input.txt"
+
+echo "./day$1 created. Ready to start!"

utils/utils.go

@@ -111,3 +111,11 @@ func Fold[A any, T any](a A, s []T, f func(A, T) A) A {
 	}
 	return a
 }
+
+func AbsInt(x int) int {
+	if x >= 0 {
+		return x
+	} else {
+		return -x
+	}
+}