Untitled

class Solution {
public:
    int longestConsecutive(vector<int>& nums) {
        int ans = 0;
        unordered_set<int> S;
        for (int n : nums) S.emplace(n);
        int cnt = 2;
        while (S.size() > 0) {
            int tmp = 1;
            int n = *S.begin();
            S.erase(n);
            int i = n;
            while (S.find(i+1)!=S.end()) { tmp++; S.erase(i+1); ++i; }
            i = n;
            while (S.find(i-1)!=S.end()) { tmp++; S.erase(i-1); --i; }
            ans = max(ans, tmp);
        }
        return ans;
    }

    // 9, 1, 4, 7, 3, -1, 0, 5, 8, 6

    // 9 - 8
    // 1 - 0
    // 4 - 3
    // 7 - 6
    // 0 - -1
    // 5 - 4
    // 8 - 7
    // 6 - 5
};