To generate and print prime numbers in a given range

/* Write a C program to generate and print prime numbers in a given *

* range. Also print the number of prime numbers */

#include stdio.h
#include conio.h
#include stdlib.h
#include math.h

void main()
{
int M, N, i, j, flag, temp, count = 0;

clrscr();

printf("Enter the value of M and N\n");
scanf("%d %d", &M,&N);

if(N < 2)
{
printf("There are no primes upto %d\n", N);
exit(0);
}
printf("Prime numbers are\n");
temp = M;

if ( M % 2 == 0)
{
M++;
}
for (i=M; i<=N; 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);
count++;
}
}
printf("Number of primes between %d and %d = %d\n",temp,N,count);
}
/*---------------------------------
Output
Enter the value of M and N
15 45
Prime numbers are
17
19
23
29
31
37
41
43
Number of primes between 15 and 45 = 8
-------------------------------------------*/

This program is an extention of the previous one. We add another extra loop to increment the number isself untill it reaches the limit set of the priniting of prime numbers. This uses the netsed FOR loop concept for execution.