Day 11: part 1

day11/day11.go

@@ -0,0 +1,154 @@
+package day11
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"slices"
+	"strings"
+)
+
+func Solution1(filepath string) int {
+	matrix := parseInputMatrix(filepath)
+	printMatrix(matrix)
+	galaxies := findGalaxies(&matrix)
+	fmt.Printf("Galaxies %d: %v\n", len(galaxies), galaxies)
+	gPairs := makePairs(galaxies)
+	fmt.Printf("All pairs: %v\n", gPairs)
+
+	result := 0
+	for _, pair := range gPairs {
+		res := naiveDistCalc(pair[0], pair[1], pair[2], pair[3])
+		// fmt.Printf("ADDING {%d, %d}, {%d, %d} = %d\n", pair[0], pair[1], pair[2], pair[3], res)
+		result += res
+	}
+	return result
+}
+
+func Solution2(filepath string) int {
+	return 0
+}
+
+func naiveDistCalc(x1, y1, x2, y2 int) int {
+	dist := 0
+
+	for x1 != x2 {
+		if x1 > x2 {
+			x1--
+		} else {
+			x1++
+		}
+		dist++
+	}
+
+	for y1 != y2 {
+		if y1 > y2 {
+			y1--
+		} else {
+			y1++
+		}
+		dist++
+	}
+
+	return dist
+}
+
+func makePairs(galaxies [][2]int) [][4]int {
+	var coordPairs [][4]int
+
+	for i := 0; i < len(galaxies); i++ {
+		for j := i + 1; j < len(galaxies); j++ {
+			newPair := [4]int{
+				galaxies[i][0],
+				galaxies[i][1],
+				galaxies[j][0],
+				galaxies[j][1],
+			}
+			coordPairs = append(coordPairs, newPair)
+		}
+	}
+
+	return coordPairs
+}
+
+func findGalaxies(matrix *[][]string) [][2]int {
+	m := *matrix
+	var gCoords [][2]int
+
+	for y, row := range m {
+		for x, el := range row {
+			if el == "#" {
+				gCoords = append(gCoords, [2]int{y, x})
+			}
+		}
+	}
+
+	return gCoords
+}
+
+func parseInputMatrix(filepath string) [][]string {
+	file, err := os.Open(filepath)
+	if err != nil {
+		log.Fatalf("Failed to open the input file with: %v\n", err.Error())
+	}
+
+	var matrix [][]string
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		matrix = append(matrix, strings.Split(scanner.Text(), ""))
+	}
+	if err = scanner.Err(); err != nil {
+		log.Fatalf("Error during reading the input file: %v\n", err.Error())
+	}
+
+	return normalizeMatrix(matrix)
+}
+
+func normalizeMatrix(matrix [][]string) [][]string {
+	var normalized [][]string
+
+	var dVertical, dHorizonatl []int
+	for x := 0; x < len(matrix[0]); x++ {
+		dup := true
+		for y := 0; y < len(matrix); y++ {
+			if matrix[y][x] == "#" {
+				dup = false
+			}
+		}
+
+		if dup {
+			dVertical = append(dVertical, x)
+		}
+	}
+	for y, row := range matrix {
+		if !slices.Contains(row, "#") {
+			dHorizonatl = append(dHorizonatl, y)
+		}
+	}
+	slices.Sort(dVertical)
+	slices.Sort(dHorizonatl)
+
+	for y := len(matrix) - 1; y >= 0; y-- {
+		newRow := make([]string, len(matrix[0]), len(matrix[0])+len(dVertical))
+		copy(newRow, matrix[y])
+		for x := len(dVertical) - 1; x >= 0; x-- {
+			newRow = slices.Insert(newRow, dVertical[x], ".")
+		}
+
+		normalized = slices.Insert(normalized, 0, newRow)
+		if _, found := slices.BinarySearch(dHorizonatl, y); found {
+			normalized = slices.Insert(normalized, 0, newRow)
+		}
+	}
+
+	return normalized
+}
+
+func printMatrix(matrix [][]string) {
+	fmt.Println("----------MATRIX START----------")
+	for _, mRow := range matrix {
+		fmt.Println(mRow)
+	}
+	fmt.Println("-----------MATRIX END----------")
+}

day11/day11_test.go

@@ -0,0 +1,21 @@
+package day11
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestSolution1(t *testing.T) {
+	cases := map[string]int{
+		"test_input11": 374,
+	}
+
+	for inputFile, expectedResult := range cases {
+		result := Solution1(inputFile)
+		if result != expectedResult {
+			t.Fatalf("Solution1() = %d, expecting %d\n", result, expectedResult)
+		} else {
+			fmt.Printf("Solution1() = %d, OK\n", result)
+		}
+	}
+}

day11/test_input11

@@ -0,0 +1,10 @@
+...#......
+.......#..
+#.........
+..........
+......#...
+.#........
+.........#
+..........
+.......#..
+#...#.....

main.go

@@ -11,6 +11,7 @@ import (
 	"advent-of-code/day08"
 	"advent-of-code/day09"
 	"advent-of-code/day10"
+	"advent-of-code/day11"
 	"fmt"
 )
 
@@ -44,4 +45,7 @@ func main() {
 
 	fmt.Printf("Day 10, solution 1: %v\n", day10.Solution1("inputs/day10"))
 	fmt.Printf("Day 10, solution 2: %v\n", day10.Solution2("inputs/day10"))
+
+	fmt.Printf("Day 11, solution 1: %v\n", day11.Solution1("inputs/day11"))
+	fmt.Printf("Day 11, solution 2: %v\n", day11.Solution2("inputs/day11"))
 }