solve: Week 01 longest consecutive sequence

Author: eunice-hong

longest-consecutive-sequence/eunice-hong.ts

@@ -0,0 +1,26 @@
+/**
+ * Finds the length of the longest consecutive elements sequence.
+ * Eliminates duplicates using a Set and only starts counting when the current number is the beginning of a sequence.
+ *
+ * @param nums - An array of integers.
+ * @returns The length of the longest consecutive sequence.
+ *
+ * Time Complexity: O(n)
+ * Space Complexity: O(n)
+ */
+function longestConsecutive(nums: number[]): number {
+  let longest = 0;
+  const numSet = new Set(nums);
+
+  for (const num of numSet) {
+    if (!numSet.has(num - 1)) {
+      let length = 1;
+      while (numSet.has(num + length)) {
+        length++;
+      }
+      longest = Math.max(length, longest);
+    }
+  }
+
+  return longest;
+}