Untitled

class Solution {
public:
    long long maxRectangleArea(vector<int>& x, vector<int>& y) {
        vector<pair<int,int>> pts;
        for(int i = 0;i < x.size(); i++){
            pts.push_back({x[i],y[i]});
        }
        sort(pts.begin(),pts.end());
        map<pair<int, int>, set<int> > mp;
        long long ans = -1;
        int a = 0;
        while(a < pts.size()){
            int b = a + 1;
            while(b < pts.size() && pts[a].first == pts[b].first)b++;
            int xx = pts[a].first;
            for(int i = a;i < b - 1; i++){
                long long st = pts[i].second, ed = pts[i+1].second;
                auto it = mp.find({st,ed});
                if(it != mp.end()){
                    ans = max(ans, (ed - st) * (xx - *it->second.rbegin()));
                }
            }
            for(int i=a;i<b;i++){
                int st = pts[i].second;
                auto it = mp.lower_bound({st , 0});
                if(it != mp.end() && it->first.first == st) it = mp.erase(it);
                while(it != mp.begin()){
                    auto it_l = prev(it);
                    if(it_l->first.second >= st)
                        it_l = mp.erase(it_l);
                    else 
                        break;
                }
            }
            for(int i=a;i<b-1;i++){
                int st = pts[i].second, ed = pts[i+1].second;
                mp[{st,ed}].insert(xx);
            }
            a = b;
        }
        return ans;
    }
};