random_shuffle not really random

Question

I\'m using the random_shuffle on a vector like this:

#include 
vector  deck;
//some code to add cards to the deck h         


        

Answer 1

You need to seed the psuedo-random number generator first using srand.

#include 
#include 

...

std::srand(std::time(0));

vector  deck;
//some code to add cards to the deck here
random_shuffle ( deck.begin(), deck.end() );

Note from link above:

Generally speaking, the pseudo-random number generator should only be seeded once, before any calls to rand(), and the start of the program. It should not be repeatedly seeded, or reseeded every time you wish to generate a new batch of pseudo-random numbers.