Problem Statement

Given two integers n and k, return all possible combinations of k numbers chosen from the range [1, n].

Each combination must be a unique set of numbers, order of which does not matter.

Examples

• Example 1:

  • Input: n = 3, k = 2
  • Expected Output: [[1, 2], [1, 3], [2, 3]]
  • Justification: [[1, 2], [1, 3], [2, 3]] are all combinations of size 2, which we can create using [1, 2, 3].

• Example 2:

  • Input: n = 4, k = 1
  • Expected Output: [[1], [2], [3], [4]]
  • Justification: [[1], [2], [3], [4]] are all combinations of size 1, which we can create using `[1, 2, 3, 4].

• Example 3:

  • Input: n = 5, k = 3
  • Expected Output: [[1, 2, 3], [1, 2, 4], [1, 2, 5], [1, 3, 4], [1, 3, 5], [1, 4, 5], [2, 3, 4], [2, 3, 5], [2, 4, 5], [3, 4, 5]]
  • Justification: We unique triplets using numbers 1 to 5, yielding ten different combinations.

Try it yourself

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