longestConsecutive_graph.java

longestConsecutive_graph.java

class Solution {
    public int longestConsecutive(int[] nums) {
        if (nums.length == 0) return 0;
        Set<Integer> set = new HashSet<>();
        for (int i = 0; i < nums.length; i++) {
            set.add(nums[i]);
        }
        int res = 1;
        for (int i = 0; i < nums.length; i++) {
            if(set.contains(nums[i]-1))   continue;
            int counter=0;
            while (set.contains(nums[i] + counter)){
                set.remove(nums[i]+counter);
                counter++;
            }
            res = Math.max(res,counter);
        }
        return res;
    }
}