Longest Chain of Consecutive Numbers

Given an unsorted array of integers nums,return the length of the longest consecutive sequence. Must run in O(n) time using a Hash Set.

Input:  nums = [100, 4, 200, 1, 3, 2]
Output: 4
Explanation: Sequence is [1,2,3,4]

export function longestConsecutive(nums: number[]): number {
  const set = new Set(nums);
  let longest = 0;

  for (const num of set) {
    if (!set.has(num - 1)) {
      let streak = 1;
      let current = num;

      while (set.has(current + 1)) {
        streak++;
        current++;
      }

      longest = Math.max(longest, streak);
    }
  }

  return longest;
}