LeetCode: Combinations Solution

Implementation

1var combine = function (n, k) {
2  const res = []
3
4  const recusion = (arr, start, k) => {
5    if (k === 0) {
6      res.push([...arr])
7      return
8    }
9
10    for (let i = start; i <= n; i++) {
11      arr.push(i)
12      recusion(arr, i + 1, k - 1)
13      arr.pop()
14    }
15  }
16
17  recusion([], 1, k)
18
19  return res
20}

References

Original problem