jhonygal8
yonatan gal
204292999

I discussed this exercise with gil grimberg and miri aframov.
I also used the site stackoverflow.com.


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=  README for ex8: sudoku and stuff  =
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=  Description:  =
==================

in this exercise we wrote a program which solves sudoku boards, and we've also
wrote 3 variations of the function k_subset which we saw in the tirgul.

I'll describe the functions i wrote:

1. find_empty_cells(board, i, j) - this function searches for empty spots in the
   board, and returns the index of the spot.

2. is_value_valid(board, i, j, num): this function checks if a given num is
   valid in the spot board[i][j].

3. solve_sudoku(board, i=0, j=0): this function is the recursive function
   which uses the previous functions and solves the sudoko.

now we have the 3 variations of the k_subsets function:

1. print_k_subsets(n, k): this is the version that we've seen in the tirgul.
   given a number n, and a number k <= n, the function prints
   all subsets of {0,…,n-1} of size exactly k.

2. fill_k_subsets(n, k, lst): given an empty lst, we fill it with all possible
   subsets of {0,...n-1} of size exactly k.

3. return_k_subsets(n, k): in this version we returned every possible subset of
   size of exactly k, but we did it without using any list as an argument.