Longest Consecutive Sequence LeetCode solution in Java

1
class Solution {
2
  public int longestConsecutive(int[] nums) {
3
    Set<Integer> storage = new HashSet();
4

5
    for (int i = 0; i < nums.length; i++) {
6
      storage.add(nums[i]);
7
    }
8

9
    int maxL = 0;
10

11
    for (int i = 0; i < nums.length; i++) {
12

13
      // check if nums[i] id present in set or not
14
      // since after checking in set we remove the element from
15
      // set, there is no double calculation for same sequence
16
      if (storage.contains(nums[i])) {
17
        storage.remove(nums[i]);
18

19
        int dec = nums[i] - 1;
20
        int inc = nums[i] + 1;
21
        int tempL = 1;
22

23
        // check both ways from nums[i] and calculate
24
        // tempL. since we are removing elements from
25
        // set we only calculate once for every sequence.
26

27
        while (storage.contains(dec)) {
28
          storage.remove(dec);
29
          dec--;
30
          tempL++;
31
        }
32

33
        while (storage.contains(inc)) {
34
          storage.remove(inc);
35
          inc++;
36
          tempL++;
37
        }
38

39
        maxL = Math.max(maxL, tempL);
40
      }
41
    }
42

43
    return maxL;
44
  }
45
}