Add solution for day 1 - part 2

Author: avolutions

src/day-1/index.ts

@@ -28,4 +28,17 @@ const distance = leftValues.reduce((sum, left, index) => {
  return sum + Math.abs(left - rightValues[index]);
 }, 0);
 
-console.log("Part 1: " + distance);
+console.log("Part 1: " + distance);
+
+// Calculate similarity score
+let similarityScore = 0;
+
+for (const leftValue of leftValues) {
+ // Count how many times the left value appears in right list
+ const appearanceInRight = rightValues.filter(rightValue => rightValue === leftValue).length;
+
+ // Calculate similarity score
+ similarityScore += (leftValue * appearanceInRight);
+}
+
+console.log("Part 2: " + similarityScore);