I am doing a 5 X 5 bingo card using C language. Obviuosly, there are 5 rows and 5 columns. What I need is to have random, non-repeating numbers per column.

Column 0 should have random, non repeating numbers from 1-15.

Column 1 should have random, non repeating numbers from 16-30.

Column 2 should have random, non repeating numbers from 31-45 (Note that this column must include the word "FREE" in the centeror third position)

Column 3 should have random, non repeating numbers from 46-60

& Column 4 should have random, non repeating numbers from 61-75.

I know how to do the grid, however, my main issue is creating random, non-repeating numbers per column. Any help will be greatly appreciated!