Practice/Atlassian/Leetcode 2353. Design a Food Rating System

Leetcode 2353. Design a Food Rating System

CodingMust

Problem

Design a data structure that manages a restaurant menu rating system. The system needs to track multiple food items, each associated with a specific cuisine type and a numerical rating. Your implementation must support two primary operations:

1. Update a food's rating: Change the rating of an existing food item
2. Query the best food: Find the highest-rated food for a given cuisine

When multiple foods in the same cuisine have identical ratings, return the one that comes first alphabetically (lexicographically smallest name).

Your FoodRatings class should be initialized with three arrays of equal length:

• foods: names of food items (all unique)
• cuisines: the cuisine type for each corresponding food
• ratings: the initial rating for each corresponding food

Requirements

1. Implement a constructor that initializes the system with the provided foods, cuisines, and ratings
2. Implement changeRating(food, newRating) that updates a specific food's rating
3. Implement highestRated(cuisine) that returns the name of the food with the highest rating for the specified cuisine
4. When multiple foods share the highest rating in a cuisine, return the lexicographically smallest name
5. All food names are guaranteed to be unique across the entire system

Constraints

• 1 ≤ foods.length ≤ 2 × 104
• foods.length = cuisines.length = ratings.length
• 1 ≤ foods[i].length, cuisines[i].length ≤ 10
• 1 ≤ ratings[i] ≤ 108
• foods[i], cuisines[i] consist of lowercase English letters
• All food names are distinct
• At most 2 × 104 calls will be made to changeRating and highestRated
• changeRating will only be called on foods that exist in the system

Examples

Example 1:

Input: Initialize: foods = ["kimchi", "bulgogi", "bibimbap"], cuisines = ["korean", "korean", "korean"], ratings = [9, 8, 10] Operations: highestRated("korean") Output: "bibimbap" Explanation: Bibimbap has the highest rating (10) among Korean foods.

Example 2:

Input: Initialize: foods = ["pad-thai", "curry", "pad-thai-gai"], cuisines = ["thai", "thai", "thai"], ratings = [7, 7, 6] Operations: highestRated("thai") Output: "curry" Explanation: Both pad-thai and curry have rating 7, but "curry" comes first alphabetically.

Example 3:

Input: Initialize: foods = ["lasagna", "tiramisu"], cuisines = ["italian", "italian"], ratings = [8, 9] Operations: 1. changeRating("lasagna", 11) 2. highestRated("italian") Output: "lasagna" Explanation: After the update, lasagna has rating 11, making it the highest-rated Italian food.