C programming, Show the prime numbers that lie within a specified range.

#include <stdio.h>

int main() {

   int low, high, i, flag;

   printf("Enter two numbers(intervals): ");

   scanf("%d %d", &low, &high);

   printf("Prime numbers between %d and %d are: ", low, high);

   while (low < high) {

      flag = 0;

      if (low <= 1) {

         ++low;

         continue;

      }

      for (i = 2; i <= low / 2; ++i) {

         if (low % i == 0) {

            flag = 1;

            break;

         }

      }

      if (flag == 0)

         printf("%d ", low);

      ++low;

   }

   return 0;

}