Create 2353. Design a Food Rating System 1 (#888)

Author: Chayandas07

2353. Design a Food Rating System 1

@@ -0,0 +1,51 @@
+class FoodRatings {
+    unordered_map<string, string> food_cuisines;
+    unordered_map<string, int> food_ratings;
+    struct Node {
+        int rating;
+        string food;
+    };
+    struct Cmp {
+        bool operator()(const Node& a, const Node& b) const {
+            if (a.rating == b.rating) return a.food > b.food; 
+            return a.rating < b.rating;                  
+        }
+    };
+    unordered_map<string, priority_queue<Node, vector<Node>, Cmp>> cuisines_heap;
+
+public:
+    FoodRatings(vector<string>& foods, vector<string>& cuisines, vector<int>& ratings) {
+        int n = (int)foods.size();
+        for (int i = 0; i < n; ++i) {
+            const string& food = foods[i];
+            const string& cuisine = cuisines[i];
+            int rating = ratings[i];
+            food_cuisines[food] = cuisine;
+            food_ratings[food] = rating;
+            cuisines_heap[cuisine].push({rating, food});
+        }
+    }
+    
+    void changeRating(string food, int newRating) {
+        const string& cuisine = food_cuisines[food];
+        food_ratings[food] = newRating;
+        cuisines_heap[cuisine].push({newRating, food});
+    }
+    
+    string highestRated(string cuisine) {
+        auto& pq = cuisines_heap[cuisine];
+        while (!pq.empty()) {
+            const auto top = pq.top();
+            if (food_ratings[top.food] == top.rating) return top.food;
+            pq.pop(); 
+        }
+        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);
+ */