# b_cubic_interpolation.py

# b_cubic_interpolation.py

def cubic(a, b, c, d):
    # Calculate the step size between the values of the corners
    step_size_1 = (b - a) / 4
    step_size_2 = (c - a) / 4
    step_size_3 = (d - (a + 4 * step_size_1 + 4 * step_size_2)) / 16

    # Initialize the grid with the corner values
    grid = [[int(a + i * step_size_1 + j * step_size_2 + (i * j) * step_size_3) for i in range(5)] for j in range(5)]
    return grid

for i in cubic(3,15,19,59):
    print(i)

'''
[3, 6, 9, 12, 15]
[7, 11, 16, 21, 26]
[11, 17, 24, 30, 37]
[15, 23, 31, 39, 48]
[19, 29, 39, 49, 59]
'''

print('.')
for i in cubic(3,15,19,99):
    print(i)

'''
[3, 6, 9, 12, 15]
[7, 14, 21, 28, 36]
[11, 22, 34, 45, 57]
[15, 30, 46, 62, 78]
[19, 39, 59, 79, 99]
'''