C++ offers the rand() function to generate pseudo-random numbers.
Here's a quick and dirty example using rand.

#include<iostream>
int main(int argc,char** argv)
{
int lowBound = 0;
int upBound = 0;
int random = 0;
//Get lower bound (a)
std::cout << "Input lower bound: ";
std::cin >> lowBound;
std::cout << std::endl;
//Get upper bound (b)
std::cout << "Input upper bound: ";
std::cin >> upBound;
std::cout << std::endl;
//Generate the random number in the range a-b using rand()
random = rand() % upBound + lowBound;
//Output
std::cout << "Here is your random number: " << random << ".\n";
return 0;
}

Hope this helps!

P.S. rand() is good, but it is far from perfect. If you need some of the advanced random distributions, you'll probably need to find a custom library - there are tons available for statistics/probability analysis.

I'd have to agree. That would be a better use since it prevents rand() from repeating it's output if given the same input. I've always hated that about rand() .