Problem with Srand.

[Blackyakuzu94]

Hey guys, I have a coin toss simulation I am trying to run, but the problem is I keep getting only one result instead of a randomized one. I went over the code and it doesn't seem like anything would be out of place. I was hoping for some tips to the problem.

#include<iostream>
#include<cstdlib>
#include<ctime>
using namespace std;

int Flip();

int main()
{

	int Heads = 0;
	int Tails = 0;
	int num;

	for (int i = 0; i < 100; i++)
	{
		num = Flip();
		if (num == 1)
		{
			cout << "Heads" << endl;
			Heads++;
		}
		else
		{
			cout << "Tails" << endl;
			Tails++;
		}

	}

	cout << "Total amount of Heads is " << Heads << endl;
	cout << "Total amount of Tails is " << Tails << endl;

	return 0;
}

int Flip()
{
	int num;
	srand((unsigned) time(0));
	num = rand() % 2;
	return num;
}

[Ganado]

The random seed should only be initialized once in the lifetime of your program.

Move line 40 to the beginning of main.

[Blackyakuzu94]

Ahh, yea that'd do it. thanks.

[1CfG1hU5]

yes agree, srand func early to initialize random generator. if called more than once, srand() will
be active throughout all of main. also:

num = rand() % 2 + 1;  // to get 1 or 2 only
                                    // sometimes rand() will exceed expected
                                    // did rand() %14+2 before and was getting 15

or could do

num = rand() %1;  // where 0 is head and 1 is tails or the opposite

or random(2) could be used

random does (num -1)

an example in one of my languages is random(100), 0 to 99