这次比较有成就感，排序之后就没什么了

class Solution {
public:
    int longestConsecutive(vector<int>& nums) {
        if(nums.empty()){
            return 0;
        }
        sort(nums.begin(),nums.end());
        int result = 0;
        int temp = 0;
        for(int i =0 ;i < nums.size()-1; i++){
            if(nums[i+1]-nums[i]==1){
                temp++;
            }
             else if(nums[i+1]-nums[i] == 0){
               continue;
            }
            else{
                result = max(temp+1,result);
                temp = 0;
            }
        }
         result = max(temp+1,result);
        return result;
    }
};