Refactor removeDuplicates

Author: sheida-shab

Sprint-1/JavaScript/removeDuplicates/removeDuplicates.mjs

@@ -1,36 +1,24 @@
 /**
  * Remove duplicate values from a sequence, preserving the order of the first occurrence of each value.
  *
- * Time Complexity:
- * Space Complexity:
- * Optimal Time Complexity:
- *
+ * Time Complexity:before refactoring O(n²)- after refactoring O(n)
+ * Space Complexity:O(n)
+ * Optimal Time Complexity:O(n)
+ 
+ * The original implementation relied on nested loops to detect duplicates,
+ *resulting in O(n²) time complexity, which does not scale well for large inputs.
+ *The refactored solution uses a Set to perform duplicate checks in constant time.
+ *This removes the need for an inner loop and reduces the overall time complexity
+ *to O(n), which is optimal for this problem.
+ *using  https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set
  * @param {Array} inputSequence - Sequence to remove duplicates from
  * @returns {Array} New sequence with duplicates removed
  */
 export function removeDuplicates(inputSequence) {
-  const uniqueItems = [];
+  const uniqueItemSet = new Set;
 
-  for (
-    let currentIndex = 0;
-    currentIndex < inputSequence.length;
-    currentIndex++
-  ) {
-    let isDuplicate = false;
-    for (
-      let compareIndex = 0;
-      compareIndex < uniqueItems.length;
-      compareIndex++
-    ) {
-      if (inputSequence[currentIndex] === uniqueItems[compareIndex]) {
-        isDuplicate = true;
-        break;
-      }
-    }
-    if (!isDuplicate) {
-      uniqueItems.push(inputSequence[currentIndex]);
-    }
+  for (let i=0 ;i<inputSequence.length;i++){
+    uniqueItemSet.add(inputSequence[i]);
   }
-
-  return uniqueItems;
+   return [...uniqueItemSet];
 }