The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference
by Nicolai M. Josuttis, Addison-Wesley, 1999
© Copyright Nicolai M. Josuttis 1999
#include <cstdlib>
#include "algostuff.hpp"
using namespace std;
class MyRandom {
public:
ptrdiff_t operator() (ptrdiff_t max) {
double tmp;
tmp = static_cast<double>(rand())
/ static_cast<double>(RAND_MAX);
return static_cast<ptrdiff_t>(tmp * max);
}
};
int main()
{
vector<int> coll;
INSERT_ELEMENTS(coll,1,9);
PRINT_ELEMENTS(coll,"coll: ");
// shuffle all elements randomly
random_shuffle (coll.begin(), coll.end());
PRINT_ELEMENTS(coll,"shuffled: ");
// sort them again
sort (coll.begin(), coll.end());
PRINT_ELEMENTS(coll,"sorted: ");
/* shuffle elements with self-written random number generator
* - to pass an lvalue we have to use a temporary object
*/
MyRandom rd;
random_shuffle (coll.begin(), coll.end(), // range
rd); // random number generator
PRINT_ELEMENTS(coll,"shuffled: ");
}