<p>Given two integers <code>n</code> and <code>k</code>, return <em>all possible combinations of</em> <code>k</code> <em>numbers chosen from the range</em> <code>[1, n]</code>.</p>

<p>You may return the answer in <strong>any order</strong>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> n = 4, k = 2
<strong>Output:</strong> [[1,2],[1,3],[1,4],[2,3],[2,4],[3,4]]
<strong>Explanation:</strong> There are 4 choose 2 = 6 total combinations.
Note that combinations are unordered, i.e., [1,2] and [2,1] are considered to be the same combination.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> n = 1, k = 1
<strong>Output:</strong> [[1]]
<strong>Explanation:</strong> There is 1 choose 1 = 1 total combination.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= n &lt;= 20</code></li>
	<li><code>1 &lt;= k &lt;= n</code></li>
</ul>

class Solution:
    def combine(self, n: int, k: int) -> List[List[int]]:
        # def combinee(lst: List[int], k: int) -> List[List[int]]:
        #     print('hello',lst,k)
        #     if k == 0:
        #         result = [[]]
        #     elif len(lst) == k:
        #         result = [lst]
        #     else:
        #         rest = combinee(lst[1:],k-1)
        #         c=[]
        #         for i in rest:
        #             d=[[]]
        #             for j in range(k):
        #                 print('before',lst,k,rest,i,j)
        #                 d += [i[:j]+[lst[0]]+i[j:]]
        #                 print('after',lst,k,rest,i,j,d)
        #             c += d[1:]
        #         result = c

        #     return result
        def combinee(lst: List[int], k: int) -> List[List[int]]:
            # print('hello',lst,k)
            result = [[]]
            if k > 0:
                for i,curr in enumerate(lst):
                    # print('  before',lst,k,curr)
                    rest = combinee(lst[i+1:],k-1)
                    # print('  after',lst,k,curr,rest)
                    result += [[curr]+resti for resti in rest]
                    # print('  after',result)
                result = result[1:]

            return result

        return combinee(list(range(1,n+1)),k)
56764