C++

For an assignment I need to have a program print the inputted number, and every number before it in sequence ex:

1
12
123
1234
12345
123456

I can get it to print a list of the number but for the love of god I cant get it to print the numbers before hand.  I know theres a simple way to do it nesting a while loop in a for loop but I can't fucking figure it out.

Help for a poor retarded aspiring programmer?

Even better, but uglier.

Prelude Data.List> let hw x = mapM_ (\xs -> (mapM_ (putStr.show) xs) >> putStrLn "") (tail.inits $ enumFromTo 1 x)
Prelude Data.List> hw 5
1
12
123
1234
12345
Prelude Data.List>