Combinations
MediumP2Coding
Return all combinations of k numbers chosen from 1..n.
Write each combination in increasing order and list the combinations in lexicographic order, for example [1,2] before [1,3].
Example 1
- Input
- n = 4, k = 2
- Output
- [[1,2],[1,3],[1,4],[2,3],[2,4],[3,4]]
- Why
- Six combinations of 2 numbers out of 4.
Example 2
- Input
- n = 1, k = 1
- Output
- [[1]]
Example 3
- Input
- n = 3, k = 3
- Output
- [[1,2,3]]
Constraints
- 1 <= n <= 20
- 1 <= k <= n
- The number of combinations is at most 200000.
Hints
Give it a real attempt first. Run shows which examples fail.
Saved automatically
Run checks the 3 visible tests, Submit all 9. ⌘Enter runs, ⌘⇧Enter submits.