#include <stdio.h>
#define MAXVALUE 16

int main()
{
    int numVals;
    int i, val;
    
    FILE *outfile = fopen("randomNums.txt", "w"); //use "r" to read from the file
    
    srand(time(0));  // randomize (re-seed) the "random" number generator
    printf("Write how many random values to the file? ");
    scanf("%d", &numVals);  // "&" means "address-of" the variable
                            // i.e. scanf reads a value into the address of
			    // the variable numVals
    fprintf(outfile, "%d\n", numVals);
    for(i = 0; i < numVals; i++)
    {
        val = rand() % 16;        // "random" numbers from 0..15
        fprintf(outfile, "%4d", val);
	if (i % 10 == 9)
	   fprintf(outfile, "\n");     // newline after each group of 10 values
    }
    
    fprintf(outfile, "\n");
    
    fclose(outfile);
    
    return 0;
}

/*
gcc -o randomNumFile randomNumFile.c 
./randomNumFile

Write how many random values to the file? 50

more randomNums.txt 
50
   9  10  10  13   2   2  14   9   8  11
  10   9   0   6  14  15  13  13   2   4
  10  13   8  10  12   2   3   1   3  11
   2  12   5  13   9   8  15   8   1   7
   3  12   0   3   2  15   2  15  12   5




*/