Thread: Generating random numbers between two inputs

Hello,

I am writing a program where a user enters two integers, a max and a min. From these two values, the program should generate 12 random numbers between those two values (inclusive). So if a user entered 10 and 22, then the answer can be : 10,11,12,13,14,15,16,17,18,19,20,21,22.

Right now I am having some difficulty with just running the program. I am getting an error that says I have too few arguments to function random_generator on lines 20-31 [the block of printf statements]

If someone can help me fix the error and make sure I am getting the random numbers it would be greatly appreciated. Thank you.

Here is the code:

Code:

//Random

#include <stdio.h>
#include <stdlib.h>
#include <time.h>



int random_generator(int minval, int maxval);

int
main(void)
{
      srand(time(NULL));
      int minval, maxval;
      printf("Enter min and max integers.");
      scanf("%i", &minval);
      scanf("%i", &maxval);
      printf("Some random integers between %i and %i are:\n", minval, maxval);
      printf("%i\n", random_generator());
      printf("%i\n", random_generator());
      printf("%i\n", random_generator());
      printf("%i\n", random_generator());
      printf("%i\n", random_generator());
      printf("%i\n", random_generator());
      printf("%i\n", random_generator());
      printf("%i\n", random_generator());
      printf("%i\n", random_generator());
      printf("%i\n", random_generator());
      printf("%i\n", random_generator());
      printf("%i\n", random_generator());


}
      int random_generator(int minval, int maxval)
     {
      return (rand()%(maxval - minval )+ minval);
     }

Originally Posted by c99tutorial

You declared random_generator to take two arguments, so you must call it each time with the two arguments, e.g.

Code:

printf("%i\n", random_generator(10,22));

By the way, the function as written will return a random value in the range [minval, maxval-1]. In other words, you will never get a random number that is as high as maxval from that function.

Oh gotcha. Thanks!

Is there some way I can get it to be [minval, maxval]?

Code:

return rand() % (maxval - minval + 1) + minval;

Thank you!