最长连续序列

Posted 2022-12-13 Alice_yufeng

class Solution 
    public int longestConsecutive(int[] nums) 
        Set<Integer> num_set = new HashSet<Integer>();
        for (int num : nums) 
            num_set.add(num);
        

        int longestStreak = 0;

        for (int num : num_set) 
            if (!num_set.contains(num - 1)) 
                int currentNum = num;
                int currentStreak = 1;

                while (num_set.contains(currentNum + 1)) 
                    currentNum += 1;
                    currentStreak += 1;
                

                longestStreak = Math.max(longestStreak, currentStreak);
            
        
        return longestStreak;