longest-consecutive-sequence

// longest-consecutive-sequence

// solution


class Solution {
public:
    int longestConsecutive(vector<int>& nums) {
        
        int n=nums.size();
        unordered_map<int,int>mp;
        
        for(int i=0;i<n;i++)
            mp[nums[i]]=0;
        
        int el1,el2,c1,c2;
        int ans=0;
        
        for(int i=0;i<n;i++){
            el1=nums[i]-1;
            el2=nums[i]+1;c1=0;c2=0;
            
            if(mp[nums[i]]==1)
                continue;
            
            while(mp.find(el1)!=mp.end()){
                c1++;
                mp[el1]=1;
              //  mp[el1]--;
                el1--;
                
            }
            while(mp.find(el2)!=mp.end()){
                c2++;
                mp[el2]=1;
               // mp[el2]--;
                el2++;
                
            }
            mp[nums[i]]=1;
            ans=max(ans,(c1+c2+1));
        }
        
        return ans;
    }
};