Question

#/usr/bin/python2.4 -tt

import sys

def mult_table(x,y):
  for i in range(1,y+1):
    for n in range(1,x+1):
      if n == 1:
        print i*n,
      elif n == x:
        print repr(i*n).rjust(3)
      else:
        print repr(i*n).rjust(3),

mult_table(12,3)
sys.exit(0)

I submitted this short program to CodeEval. Its only job is to make a multiplication table. The problem is that it should not have any trailing whitespace and when I submitted it the last line has a space after the 36. I tested myself, and I don’t have this problem. What is going on?

Answer 1

Your code adds a space for mult_table(1,1) not for mult_table(12,3).

So you need to fix your if n == 1 case (to also check n == x, as you do later in the code).

I would do this a bit differently, so that the heart of mult_table is something like:

      if n == 1:
        print i*n,
      else:
        print repr(i*n).rjust(3),

And then just print your newline in the outer for loop.

Take-home: Test your boundary conditions! 🙂