Longest Consecutive Sequence

1public int longestConsecutive(int[] nums) {
2    if (nums.length == 0) return 0;
3
4    Set<Integer> numSet = new HashSet<>();
5    for (int num : nums) {
6        numSet.add(num);
7    }
8
9    int longestStreak = 0;
10
11    for (int num : numSet) {
12        // Check if num is the beginning of a sequence
13        if (!numSet.contains(num - 1)) {
14            int currentNum = num;
15            int currentStreak = 1;
16
17            // Increment currentNum to count the length of sequence
18            while (numSet.contains(currentNum + 1)) {
19                currentNum += 1;
20                currentStreak += 1;
21            }
22
23            longestStreak = Math.max(longestStreak, currentStreak);
24        }
25    }
26    return longestStreak;
27}