Combination Sum III
Find all valid combinations of k numbers that sum up to n such that the following conditions are true:
- Only numbers
1through9are used. - Each number is used at most once.
Return a list of all possible valid combinations. The list must not contain the same combination twice, and the combinations may be returned in any order.
Example 1
Input
k = 3, n = 7Output
[[1,2,4]]1 + 2 + 4 = 7, and there are no other valid combinations.
Example 2
Input
k = 3, n = 9Output
[[1,2,6],[1,3,5],[2,3,4]]The valid combinations are 1 + 2 + 6 = 9, 1 + 3 + 5 = 9, and 2 + 3 + 4 = 9.
Constraints
- 2 <= k <= 9
- 1 <= n <= 60