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?

>>13
variable declarations in for statement are only valid in C99
I'm surprised by that. Why bother with an initialization expression at all if you can't declare variables in it? That's its the idiomatic purpose. I wonder if there was a good reason not to support that.