Is Patients With a Condition easy or hard?

Patients With a Condition is classified as an Easy database problem. The main challenge is avoiding partial matches like DIAB100 and ensuring DIAB1 appears as a separate code in the conditions string.

Patients With a Condition Python/Java solution

Python and JavaScript solutions often split the conditions string and check whether DIAB1 appears as an exact token. Java and C# implementations frequently use regex patterns such as (^|\\s)DIAB1(\\s|$) to guarantee correct word boundaries.

How to solve Patients With a Condition in O(n)?

You iterate through the patient rows once and check the conditions string using either token comparison or a regex boundary match. Each row requires scanning the condition text, which makes the effective complexity O(n * m). Using a regex such as (^|\\s)DIAB1(\\s|$) ensures accurate detection in a single pass.

What is the best approach for Patients With a Condition?

Regular expression matching is usually the best approach because it enforces word boundaries and prevents partial matches such as DIAB100. A pattern like (^|\\s)DIAB1(\\s|$) checks that DIAB1 appears as a standalone code. The solution scans each row once with O(n * m) time complexity.

Is Patients With a Condition asked at Google/Amazon/Meta?

Database filtering problems like this appear frequently in SQL interview rounds at companies such as Amazon and Meta. They test your ability to work with string fields, pattern matching, and query conditions rather than complex algorithms.

What data structure is used in Patients With a Condition?

The problem mainly uses string processing rather than advanced data structures. The conditions column behaves like a space-separated list, so solutions rely on string tokenization or regular expression matching.

What is the time complexity of Patients With a Condition?

Both common approaches run in O(n * m) time, where n is the number of patient rows and m is the average length of the conditions string. Each row must be scanned to detect the DIAB1 code. Space complexity ranges from O(1) with regex matching to O(m) when splitting the string into tokens.

1527. Patients With a Condition - Practice Online

Table: Patients

+--------------+---------+
| Column Name  | Type    |
+--------------+---------+
| patient_id   | int     |
| patient_name | varchar |
| conditions   | varchar |
+--------------+---------+
patient_id is the primary key (column with unique values) for this table.
'conditions' contains 0 or more code separated by spaces. 
This table contains information of the patients in the hospital.

Write a solution to find the patient_id, patient_name, and conditions of the patients who have Type I Diabetes. Type I Diabetes always starts with DIAB1 prefix.

Return the result table in any order.

The result format is in the following example.

Example 1:

Input: 
Patients table:
+------------+--------------+--------------+
| patient_id | patient_name | conditions   |
+------------+--------------+--------------+
| 1          | Daniel       | YFEV COUGH   |
| 2          | Alice        |              |
| 3          | Bob          | DIAB100 MYOP |
| 4          | George       | ACNE DIAB100 |
| 5          | Alain        | DIAB201      |
+------------+--------------+--------------+
Output: 
+------------+--------------+--------------+
| patient_id | patient_name | conditions   |
+------------+--------------+--------------+
| 3          | Bob          | DIAB100 MYOP |
| 4          | George       | ACNE DIAB100 | 
+------------+--------------+--------------+
Explanation: Bob and George both have a condition that starts with DIAB1.