Ok, these kinds of problem scream out to use a while loop, so let's see how it might work with that:
This works just like the odometer on your car, with three being the far right hand "wheel", and two being one wheel to the left of that, and etc.
set char's one, two, and three to @ //one less than A
get a number from the user, or a file.
while(number > 0)
if(three > 'Z')
then increment two and set three = 'A'
Extend the three if statement, to include two, so if two > 'Z', the one
wheel, will be incremented, and two and three reset to 'A'
and loop back
if one equals '@' then one = 32
if two equals '@') then two = 32
print num was: %d, which is: %c%c%c num, one, two, three.
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When you're programming, you'll refer to it frequently.