can any1 give me flowchart and algorithm for
1) counting positive numbers from a given set
2) gcd and lcm of two numbers
3) smallest positive divisor of an integer other than 1
so from above i would be able to make program on my own

That isn't what we do here. ;)

We help YOU when you are stuck with some C programming problem, but we don't supply algorithms or large blocks of code for you, on request.

You get started on your program, and if you hit a problem you can't solve, then you post the code (so we know what you're talking about), and give the specifics of your problem.

Then we can nearly always help.

And do you REALLY require an algorithm to count up the positive numbers from a set?

Please -- say it ain't so!