refactor code for find commonItems

Author: sheetalkharab

Sprint-1/JavaScript/findCommonItems/findCommonItems.js

@@ -1,14 +1,25 @@
 /**
  * Finds common items between two arrays.
  *
- * Time Complexity:
- * Space Complexity:
- * Optimal Time Complexity:
+ * Time Complexity:O(n+m) it build set and loop through arrays once
+ * Space Complexity: store second array in set
+ * Optimal Time Complexity:O(m+n)
  *
  * @param {Array} firstArray - First array to compare
  * @param {Array} secondArray - Second array to compare
  * @returns {Array} Array containing unique common items
  */
-export const findCommonItems = (firstArray, secondArray) => [
-  ...new Set(firstArray.filter((item) => secondArray.includes(item))),
-];
+// export const findCommonItems = (firstArray, secondArray) => [
+//   ...new Set(firstArray.filter((item) => secondArray.includes(item))),
+// ];
+// Refactored to use a Set for faster lookups, making the code more efficient
+export const findCommonItems = (firstArray, secondArray) => {
+  const secondArraySet = new Set(secondArray);
+  const resultSet = new Set();
+  for (const element of firstArray) {
+    if (secondArraySet.has(element)) {
+      resultSet.add(element);
+    }
+  }
+  return [...resultSet];
+};