Design a Food Rating System | Leetcode 2353

class FoodRatings {
    #define pis pair<int,string>

    struct compare {
        bool operator()(const pis& a, const pis& b) const {
            if (a.first != b.first)
                return a.first < b.first;   // higher rating = higher priority
            return a.second > b.second;     // lexicographically smaller name = higher priority
        }
    };

    unordered_map<string,pis> food_rating_cuisine;
    unordered_map<string,priority_queue<pis,vector<pis>,compare>> cuisine_maxheap;
public:
    FoodRatings(vector<string>& foods, vector<string>& cuisines, vector<int>& ratings) {
        for(int i=0;i<foods.size();++i){
            food_rating_cuisine[foods[i]] = make_pair(ratings[i],cuisines[i]);
            cuisine_maxheap[cuisines[i]].push({ratings[i],foods[i]});
        }
    }
    
    void changeRating(string food, int newRating) {
        food_rating_cuisine[food].first = newRating;
        cuisine_maxheap[food_rating_cuisine[food].second].push({newRating,food});
    }
    
    string highestRated(string cuisine) {
        while(!cuisine_maxheap.empty()){
            pis curr = cuisine_maxheap[cuisine].top();
            cuisine_maxheap[cuisine].pop();

            if(food_rating_cuisine[curr.second].first == curr.first){
                cuisine_maxheap[cuisine].push(curr);
                return curr.second;
            }
        }
        return "";
    }
};

/**
 * Your FoodRatings object will be instantiated and called as such:
 * FoodRatings* obj = new FoodRatings(foods, cuisines, ratings);
 * obj->changeRating(food,newRating);
 * string param_2 = obj->highestRated(cuisine);
 */