feat: day 01 part 2 solution

Author: agrmohit

2024/01/main.go

@@ -30,8 +30,30 @@ func solvePart1(input string) int {
 	return totalDistance
 }
 
+func solvePart2(input string) int {
+	left, right, err := inputs.ExtractIntPairs(input)
+	if err != nil {
+		panic(err)
+	}
+
+	rightCount := make(map[int]int)
+	similarityScore := 0
+
+	for _, rnum := range right {
+		rightCount[rnum]++
+	}
+
+	for _, lnum := range left {
+		similarityScore += lnum * rightCount[lnum]
+	}
+
+	return similarityScore
+}
+
 func main() {
 	part1Solution := solvePart1(input)
+	part2Solution := solvePart2(input)
 
 	fmt.Println("Day 01 Part 1 solution:", part1Solution)
+	fmt.Println("Day 01 Part 2 solution:", part2Solution)
 }

2024/01/main_test.go

@@ -9,12 +9,21 @@ import (
 var test1 string
 
 func TestSolution(t *testing.T) {
-	t.Run("Day 01 part 1 test 1", func(t *testing.T) {
+	t.Run("Day 01 part 1", func(t *testing.T) {
 		want := 11
 		got := solvePart1(test1)
 
 		if got != want {
 			t.Errorf("Incorrect solution, got %d want %d", got, want)
 		}
 	})
+
+	t.Run("Day 01 part 2", func(t *testing.T) {
+		want := 31
+		got := solvePart2(test1)
+
+		if got != want {
+			t.Errorf("Incorrect solution, got %d want %d", got, want)
+		}
+	})
 }