Combination Sum
Medium
Question
Given a list of unique positive integers and a target, find all unique combinations in the list where its sum is equal to the target.
Input: nums = [2, 3, 5], target = 8
Output: [[2, 2, 2, 2], [2, 3, 3], [3, 5]]
There are 3 unique combinations that sum up to 8.
- 2 + 2 + 2 + 2
- 2 + 3 + 3
- 3 + 5
Input: nums = [2, 4, 6, 8], target = 8
Output: [[2, 2, 2, 2], [2, 2, 4], [2, 6], [4, 4], [8]]
There are 5 unique combinations that sum up to 8.
- 2 + 2 + 2 + 2
- 2 + 2 + 4
- 2 + 6
- 4 + 4
- 8
Input: nums = [2, 4, 6, 8], target = 9
Output: []
There are no combinations that sum up to 9.
Clarify the problem
What are some questions you'd ask an interviewer?
Understand the problem
How many unique combinations are there when nums = [2, 3, 7] and target = 7?
1
2
3
4
Take a moment to understand the problem and think of your approach before you start coding.
