RNG using only system();

[Iaccidentallytwink]

So I have a school assignment, I'm supposed to make an RNG in C++ using 1 - 300 that don't repeat. Obviously, this is, at the very least, an easy assignment (if not retarded). So, what I plan on doing is trolling them a bit, and make an RNG using only system(); to do ALL the calculations and outputs. Essentially, I'm writing the RNG in batch. Problem is, I can't find a working RNG. I currently have the following for my actual number calculations:

set /a X=%random%%300

The problem with this is, using it multiple times in a row ALWAYS displays the same number. I'm stumped as to how to change this. I'm intent on sticking to using system only for it, and I'm wondering if anyone knew a way around this problem.

+3 Rep to whoever helps me out.

[Krillere]

I'm sorry, but what the hell is RNG?!

[MaiN]

I'm sorry, but what the hell is RNG?!

Random Number Generator.

[Krillere]

Ah ok. Thanks.

[Iaccidentallytwink]

Noone knows? It's due Wednesday >.>

[piller]

try something like this

#include <stdlib.h>
int min=1,max=300,randomnum;

int main(...) {
  init();
  ...
  do();
  do();
  return 0;
}

void init() {
  srand(time(NULL));
}

void do() {
  randomnum = min + rand()%(max-min+1);
}

and if you want to be sure none of the random numbers generated get repeated, put them in a stringlist or something like that and check the list every time you generate a new "random" number.

but if you use the srand(time(NULL)); i dont think you´ll get same number twice ^^


hope this helps

[piller]

omg. just saw the title : RNG using only system();

[Cypher]

@The OP:
You're doing it wrong.

[Iaccidentallytwink]

@The OP:
You're doing it wrong

I know why it's generating the same number, of course.
I was just wondering if there's anything I can do about it.

[RedArray]

By now you have already turned this in and given up on this I'm sure. Not entirely sure if this will work as I haven't done EXACTLY what you are attempting to do using *shudder* system. But it's repeating the same number because "random" numbers are generated using the current time, and if you are asking it to produce numbers one immediately after the other it will always be the same until the time changes.

So basically

while(true)
{
system("whateverthehellyouaredoing");
Sleep(100);
}

Probably have to increase the Sleep time to get a different number every time but the the concept still applies.