In this guide, you will get 3554. Find Category Recommendation Pairs LeetCode Solution with the best time and space complexity. The solution to Find Category Recommendation Pairs problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.
Problem Statement of Find Category Recommendation Pairs
Table: ProductPurchases
+————-+——+
| Column Name | Type |
+————-+——+
| user_id | int |
| product_id | int |
| quantity | int |
+————-+——+
(user_id, product_id) is the unique identifier for this table.
Each row represents a purchase of a product by a user in a specific quantity.
Table: ProductInfo
+————-+———+
| Column Name | Type |
+————-+———+
| product_id | int |
| category | varchar |
| price | decimal |
+————-+———+
product_id is the unique identifier for this table.
Each row assigns a category and price to a product.
Amazon wants to understand shopping patterns across product categories. Write a solution to:
Find all category pairs (where category1 < category2)
For each category pair, determine the number of unique customers who purchased products from both categories
A category pair is considered reportable if at least 3 different customers have purchased products from both categories.
Return the result table of reportable category pairs ordered by customer_count in descending order, and in case of a tie, by category1 in ascending order lexicographically, and then by category2 in ascending order.
The result format is in the following example.
User 1 purchased products from Books (102) and Clothing (201)
User 2 purchased products from Books (102, 103) and Clothing (201)
User 5 purchased products from Books (102, 103) and Clothing (201, 202)
Total: 3 customers purchased from both categories
Books-Electronics:
User 1 purchased products from Books (102) and Electronics (101)
User 2 purchased products from Books (102, 103) and Electronics (101)
User 3 purchased products from Books (103) and Electronics (101)
Total: 3 customers purchased from both categories
Clothing-Electronics:
User 1 purchased products from Clothing (201) and Electronics (101)
User 2 purchased products from Clothing (201) and Electronics (101)
User 4 purchased products from Clothing (201) and Electronics (101)
Total: 3 customers purchased from both categories
Electronics-Sports:
User 1 purchased products from Electronics (101) and Sports (301)
User 3 purchased products from Electronics (101) and Sports (301)
User 4 purchased products from Electronics (101) and Sports (301)
Total: 3 customers purchased from both categories
Other category pairs like Clothing-Sports (only 2 customers: Users 1 and 4) and Books-Kitchen (only 1 customer: User 3) have fewer than 3 shared customers and are not included in the result.
The result is ordered by customer_count in descending order. Since all pairs have the same customer_count of 3, they are ordered by category1 (then category2) in ascending order.
3554. Find Category Recommendation Pairs LeetCode Solution in C++
WITH
UserCategories AS (
SELECT DISTINCT
ProductPurchases.user_id,
ProductInfo.category
FROM ProductPurchases
INNER JOIN ProductInfo
USING (product_id)
),
CategoryPairs AS (
SELECT
UserCategories.user_id,
LEAST(
UserCategories.category,
UserCategories2.category
) AS category1,
GREATEST(
UserCategories.category,
UserCategories2.category
) AS category2
FROM UserCategories
INNER JOIN UserCategories AS UserCategories2
ON (
UserCategories.user_id = UserCategories2.user_id
AND UserCategories.category < UserCategories2.category)
),
PairCustomerCounts AS (
SELECT
category1,
category2,
COUNT(DISTINCT user_id) AS customer_count
FROM CategoryPairs
GROUP BY 1, 2
)
SELECT
category1,
category2,
customer_count
FROM PairCustomerCounts
WHERE customer_count >= 3
ORDER BY customer_count DESC, category1, category2; /* code provided by PROGIEZ */
3554. Find Category Recommendation Pairs LeetCode Solution in Java
N/A // code provided by PROGIEZ
3554. Find Category Recommendation Pairs LeetCode Solution in Python
