Re: Unique Random Numbers

From:
"Alexander D. B. Kim" <alexdbkim@gmail.com>
Newsgroups:
comp.lang.c++
Date:
26 Mar 2007 01:57:09 -0700
Message-ID:
<1174899429.523539.217660@l75g2000hse.googlegroups.com>
How about just make the array first and then mixing the numbers by
using the random function?

For example...

#include <cstdlib>
#include <ctime>

int main()
{
   srand(time(0));
   int arr[20] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19};
   int repeat = rand() % HOW_MANY_TIMES_DO_YOU_WANT;
   int pos = 0;

   for (int i = 0; i < repeat; ++i)
   {
     pos = rand() % 20;

     if(pos == 19)
        swap(0, 19); // Swapping the first and the last
     else
        swap(pos, pos+1); // Swapping with the next
   }
   return 0;
}

I just made the source code without thinking deeply and using IDE so
if there is a silly mistake then please forgive me =)

Cheers,

On Mar 26, 10:29 am, "Jim Langston" <tazmas...@rocketmail.com> wrote:

"Xoomer" <shah...@gmail.com> wrote in message

news:1174833087.549940.19520@d57g2000hsg.googlegroups.com...

Hi,

Can some post a code with simple Unique Random Numbers.

Random numbers stored in arr[20] but unique.


Unique, but sorted.

#include <iostream>
#include <string>
#include <set>
#include <ctime>

int main()
{
    std::set<int> RandomNumbers;
    std::srand( std::clock() );

    while ( RandomNumbers.size() < 20 )
        RandomNumbers.insert( RandomNumbers.end(), rand() );

    for ( std::set<int>::iterator it = RandomNumbers.begin(); it !=
RandomNumbers.end(); ++it )
        std::cout << *it << " ";
    std::cout << std::endl;

    std::string wait;
    std::getline( std::cin, wait );

}

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