Given a list of integers, return a list of all values that appear more than once. The result should contain each duplicate value only once and be sorted in ascending order. For null input return null, for empty list return empty list.
Examples:
Input: numbers = [1, 2, 3, 2, 4, 3, 5]
Output: [2, 3]
Explanation: 2 and 3 appear more than once, returned in ascending order
Input: numbers = [1, 1, 1, 1]
Output: [1]
Explanation: 1 appears multiple times but is only included once in result
Input: numbers = [1, 2, 3]
Output: []
Explanation: No duplicates found, return empty list
Apex Code Editor
Welcome to Lightning Challenge!
Create an Account
Sign up to track your progress, earn points, and compete with others. Your solutions will be saved automatically.
Create accountHow It Works
- • Write your solution in the code editor
- • Connect your Salesforce org to test
- • Submit to check if your solution passes
- • Use hints if you get stuck
Note
You can test your code by connecting to Salesforce, but to save your progress and earn points, you'll need to create an account. Your solutions and achievements will be tracked automatically once you're logged in.