C++ compose all possible combinations of a string from numbers, with a certain length?

Question

C++ / C#

We need to make an algorithm in C++ to make all combinations of numbers in the range from 1 to N, with a certain length K.
Sample input:
N = 2
K = 2
Sample output:
11
12
21
22

Answer 1

If I have not forgotten the combinatorics, then this is an arrangement with repetitions from N to K. The implementation in Google is quietly looking for.
https://prog-cpp.ru/placement/