Thread: Urgent help needed!!!

Write a program that produces 20 random numbers between 1 and 20. The program should store all nonduplicate values in an array.
Use the smallest possible array to accomplish this task.


I can get the numbers generated no problem however, i can't get my program to check against the array to se if the value has been stored or not...

Here is my code thus far:

Code:

#include <stdlib.h>
#include <stdio.h>
#define val 20	/*variable to be stored in the array*/				
int main()
{

	int i,x;
	int array[val];
	for ( i = 1; i <= 20; i++ ) 
	{
		x = 1 + (rand() % 20);
		array[val]=x;
		printf("%d", array[val]);
		printf("\n");
	}
  
  printf("\n");
  return 0;
}

[edit]Code tags added by Hammer.

>i can't get my program to check against the array to se if the value has been stored or not...

You could use a loop within the loop for this to check if the value is already present in the array. Don't forget that if you have read in only N values, you must check only the first N values, since a duplicate value might be present after N. Such looks like this.

Code:

for (n = 0; n < MAX; n++)
{
    value = get_value ();

    /* Check if value already in array */
    duplicate_found= false;
    for (m = 0; m < n; m++)
    {
        if (array [m] == value)
        {
            duplicate_found = true;
        }
    }

    ....
}