Combination Sum
Examples
Example 1:
Input: nums = [2,5,6,9]
target = 9
Output: [[2,2,5],[9]]
Explanation:
Example 2:
Input: nums = [3,4,5]
target = 16
Output: [[3,3,3,3,4],[3,3,5,5],[4,4,4,4],[3,4,4,5]]
Example 3:
Input: nums = [3]
target = 5
Output: []