public int longestConsecutive(int[] nums) {

if(nums.length==0)

return 0;

Arrays.sort(nums);

int max_len = 1;

int num = 1;

for (int i = 1; i < nums.length; i++) {

if(nums[i] - nums[i - 1] == 0)

continue;

if (nums[i] - nums[i - 1] == 1)

num += 1;

else {

num = 1;

}

if (num >= max_len)

max_len = num;

}

return max_len;

}