LeetCode 1398: Customers Who Bought Products A and B but Not C Solution

Master LeetCode problem 1398 (Customers Who Bought Products A and B but Not C), a medium challenge, with our optimized solutions in Java, C++, and Python. Explore detailed explanations, test your code in our interactive editor, and prepare for coding interviews.

1398. Customers Who Bought Products A and B but Not C

Medium

Database

Problem Explanation

Explanation:

To solve this problem, we can iterate through the given list of transactions and keep track of customers who bought products A and B but not C. We can use a hashmap to store the count of each product bought by each customer. Then, we can iterate through the hashmap to identify customers who bought products A and B but not C.

Create a hashmap to store the count of each product bought by each customer.
Iterate through the transactions list to populate the hashmap.
Iterate through the hashmap to identify customers who bought products A and B but not C.
Return the list of customer IDs who satisfy the condition.

Time Complexity: O(N), where N is the number of transactions. Space Complexity: O(N), where N is the number of transactions.

Solution Code

import java.util.*;

class Solution {
    public List<Integer> peopleBoughtProducts(List<List<String>> products) {
        Map<Integer, Map<String, Integer>> customers = new HashMap<>();
        Set<Integer> result = new HashSet<>();
        
        for (List<String> product : products) {
            int id = Integer.parseInt(product.get(0));
            String item = product.get(1);
            
            if (!customers.containsKey(id)) {
                customers.put(id, new HashMap<>());
            }
            customers.get(id).put(item, customers.get(id).getOrDefault(item, 0) + 1);
            
            if (customers.get(id).containsKey("A") && customers.get(id).containsKey("B") && !customers.get(id).containsKey("C")) {
                result.add(id);
            }
        }
        
        return new ArrayList<>(result);
    }
}

Try It Yourself

Loading code editor...

Frequently Asked Questions

How to solve LeetCode 1398 (Customers Who Bought Products A and B but Not C)?

This page provides optimized solutions for LeetCode problem 1398 (Customers Who Bought Products A and B but Not C) in Java, C++, and Python, along with a detailed explanation and an interactive code editor to test your code.

What is the time complexity of LeetCode 1398 (Customers Who Bought Products A and B but Not C)?

The time complexity for LeetCode 1398 (Customers Who Bought Products A and B but Not C) varies by solution. Check the detailed explanation section for specific complexities in Java, C++, and Python implementations.

Can I run code for LeetCode 1398 on DevExCode?

Yes, DevExCode provides an interactive code editor where you can write, test, and run your code for LeetCode 1398 in Java, C++, or Python.

Back to LeetCode Solutions