Optimize hasPairWithSum using a Set

Author: shreefAhmedM

Sprint-1/JavaScript/findCommonItems/findCommonItems.js

@@ -1,17 +1,13 @@
 /**
  * Finds common items between two arrays.
- *
- * Time Complexity:
- * Space Complexity:
- * Optimal Time Complexity:
+ * 
+ * Time Complexity: O(n * m)
+ * Space Complexity: O(n)
+ * Optimal Time Complexity: O(n + m)
  *
  * @param {Array} firstArray - First array to compare
  * @param {Array} secondArray - Second array to compare
  * @returns {Array} Array containing unique common items
- * 
- * Time Complexity: O(n * m)
- * Space Complexity: O(u)
- * Optimal Time Complexity: O(n + m)
  */
 export const findCommonItems = (firstArray, secondArray) => {
   const allowedItems = new Set(secondArray);
@@ -24,6 +20,13 @@ export const findCommonItems = (firstArray, secondArray) => {
 
 console.log(findCommonItems([2, 5, 7], [5, 6, 7]));
 
-// Time:O(n \ m)	filter() visits each item in the first array, and includes() may scan the second array each time.
-// Sace: O(k)	The Set stores unique common items, and the resulting array contains those items.
-// Optimal time: O(n+m) Achievable on average using a Set for efficient lookups.
+
+// Time Complexity: O(n + m) on average.
+// Building the Set takes O(m), and filtering the first array takes O(n)
+// on average because Set.has() provides efficient lookups.
+
+// Space Complexity: O(n + m).
+// The Set stores elements from secondArray, while the filter result
+// and the Set of unique common items require additional space.
+
+// Improvement: Reduces average time complexity from O(n * m) to O(n + m).

Sprint-1/JavaScript/hasPairWithSum/hasPairWithSum.js

@@ -26,3 +26,7 @@ export function hasPairWithSum(numbers, target) {
   return false;
 
 }
+
+
+// Time Complexity: O(n) We check each number once.
+// Space Complexity: O(n) The Set may store all n numbers.