Random Numbers

[Stopher]

Is there an easy way to generate random integers? or doubles? or whatevers?

Thanx,
Da Stopher

 

[pankajkumar]

Use rand function example given in msdn or one rerence which i gave in response to qs "Random number output to text file" here...anyway i repeat
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>

int main(int argc, char* argv[])
{
int i;
FILE *fp;
fp=fopen(&quot;c:\\newtext.txt&quot;,&quot;w+&quot;

/* Seed the random-number generator with current time so that
* the numbers will be different every time we run.
*/
srand( (unsigned)time( NULL ) );

/* Display 10 numbers. */
for( i = 0; i < 10;i++ )
{
char szTemp[64];
printf( &quot; %6d\n&quot;, rand() );
_itoa(rand(),szTemp,10);
strcat(szTemp,&quot; &quot;
fputs(szTemp,fp);
}
fclose(fp);
return 0;
}
hope it helps

 

[BoulderBum]

To elaborate, a call to rand() generates psuedo-random numbers, or &quot;random&quot; numbers that follow a mathmatical pattern. This, of course, isn't truly random, so a &quot;seed&quot; is thrown in to change the pattern of rand() to appear not so random. srand() accmoplishes this, and by passing an ever-changing arguement like system time to srand ( srand( time( 0 ) ) ) you get the effect of actual random numbers.

rand() &quot;returns a value between(inclusive) 0 and and RAND_MAX (defined by the compiler, often 32767). &quot; so to get a random number between a certain range say 0-10, you need to use the modulus operator to shrink the range: rand() % 11. If you want to get a random number between, say 5 and 15 you simply do as above, but use an offset ( 5 in this case so... rand % 11 + 5 ).

 

[Stopher]

That did the trick...thanx guys

Thanx,
Da Stopher