chore(aoc-2024): day1 part 2

Signed-off-by: Márk Kővári <kovarimarkofficial@gmail.com>

Author: markkovari

2024/cmd/01.go

@@ -41,6 +41,16 @@ func sortInput(left, right []int64) ([]int64, []int64) {
 	return left, right
 }
 
+func getDistancesWithSimilarity(left, right []int64) []int64 {
+	similarity := getSimilarity(right)
+	distances := make([]int64, 0)
+	for i := 0; i < len(left); i++ {
+		value := left[i] * int64(similarity[left[i]])
+		distances = append(distances, value)
+	}
+	return distances
+}
+
 func getDistances(left, right []int64) []int64 {
 	distances := make([]int64, 0)
 	for i := 0; i < len(left); i++ {
@@ -57,3 +67,16 @@ func sumDistances(distances []int64) int {
 	}
 	return sum
 }
+
+func getSimilarity(numbers []int64) map[int64]int {
+	similarity := make(map[int64]int)
+	for _, number := range numbers {
+		if _, ok := similarity[number]; ok {
+			similarity[number]++
+		} else {
+			similarity[number] = 1
+		}
+	}
+
+	return similarity
+}

2024/cmd/01_test.go

@@ -15,6 +15,18 @@ func TestExample(t *testing.T) {
 	}
 }
 
+func TestExampleSecond(t *testing.T) {
+	left, right, err := readFile("../data/01/example")
+	if err != nil {
+		t.Fatalf("Error reading file: %v", err)
+	}
+	distances := getDistancesWithSimilarity(left, right)
+	distanceSum := sumDistances(distances)
+	if distanceSum != 31 {
+		t.Fatalf("Expected 31, got %d", distanceSum)
+	}
+}
+
 func TestInput(t *testing.T) {
 	left, right, err := readFile("../data/01/input")
 	if err != nil {
@@ -27,3 +39,15 @@ func TestInput(t *testing.T) {
 		t.Fatalf("Expected 1970720, got %d", distanceSum)
 	}
 }
+
+func TestInputSecond(t *testing.T) {
+	left, right, err := readFile("../data/01/input")
+	if err != nil {
+		t.Fatalf("Error reading file: %v", err)
+	}
+	distances := getDistancesWithSimilarity(left, right)
+	distanceSum := sumDistances(distances)
+	if distanceSum != 17191599 {
+		t.Fatalf("Expected 17191599, got %d", distanceSum)
+	}
+}