Danielle - Zero Matrix Methods

[danimetz]

Time Complexity: O(2n*m)
Space Complexity: O(n+m)

[shrutivanw]

Nice work!
👍

You're on the right track. There is one consideration that your current algorithm is missing.
Consider this test case:
The input, original matrix is:

1 1 1 0 0
1 1 1 1 1
1 0 1 1 1
1 1 1 1 1

Manually visualizing this matrix, the matrix is expected to be changed to:

0 0 0 0 0
1 0 1 0 0
0 0 0 0 0
1 0 1 0 0

Your algorithm converts it to:

0 0 0 0 0
1 0 1 0 1
0 0 0 0 0
1 0 1 0 1

To account for this and some other scenarios, I added more test cases to the spec file this morning:

    it "not all rows, not all columns" do
      # setup
      rows = 4
      columns = 5
      matrix = initialize_matrix(rows, columns)
      matrix[0][3] = 0 # row 0, column 1
      matrix[0][4] = 0 # row 1, column 1
      matrix[2][1] = 0 # row 2, column 1
      rows_array = [0, 2]
      columns_array = [1, 3, 4]

      # method call
      matrix_convert_to_0(matrix)

      # validation
      verify_matrix(matrix, rows_array, columns_array)
    end

Hint: your algorithm is breaking too soon and not accounting for the last column needing to be converted to zero.