C Program 09

9.            Find the average of prime numbers in a group of N numbers using function.

 

    #include <stdio.h>

    #include <stdlib.h>

     void main()

    {

               int num1, num2, i, j;

               clrscr();

               printf("Enter the value of num1 and num2 \n");

               scanf("%d %d", &num1, &num2);

                if (num2 < 2)

               {

               printf("There are no primes upto %d\n", num2);

 

               exit(0);

               }

               else

               {

        avgprime();

               }

               getch();

    }

 

avgprime(int num1, int num2)

{

               int i, j, temp, sum=0, count=0, flag;

               float avg=0.0;

               printf("Prime numbers are \n");

               temp = num1;

               if ( num1 % 2 == 0)

               {

                    num1++;

               }

               for (i = num1; i<= num2; i = i + 2)

               {

                   flag = 0;

                   for (j = 2; j <= i / 2; j++)

                   {

                               if ((i % j) == 0)

                               {

                                   flag = 1;

                                   break;

                               }

                   }

                   if (flag == 0)

                   {

                               printf("%d\n", i);

                               sum=sum+i;

                               count++;

                   }

               }

 

               avg=(float)sum/count;

               printf("\nAverage of prime numbers=%f",avg);

               printf("\nNumber of primes between %d & %d = %d\n", temp, num2, count);

}