finding prime numbers between a given range

#include<iostream>
#include<conio.h>
using namespace std;
int main()
{
  // Declare the variables
    int a, b, i, j, flag;
int t;//test cases
  cin>>t;
  for(int k=0;k<t;k++)
  {
    // Ask user to enter lower value of interval
    cout << "Enter lower bound and upper bound of the interval: ";
    cin >> a; // Take input
 
    // Ask user to enter upper value of interval
   // cout << "\nEnter upper bound of the interval: ";
    cin >> b; // Take input
     // Print display message
    cout << "\nPrime numbers between " 
         << a << " and " << b << " are:\n";
 
    // Traverse each number in the interval
    // with the help of for loop
    for (i = a; i <= b; i++) 
    {
        // Skip 0 and 1 as they are
        // niether prime nor composite
        if (i == 1 || i == 0)
            continue;
 
        // flag variable to tell
        // if i is prime or not
        flag = 1;
 
        for (j = 2; j <= i / 2; ++j) 
        {
            if (i % j == 0) 
            {
                flag = 0;
                break;
            }
        }
 
        // flag = 1 means i is prime
        // and flag = 0 means i is not prime
        if (flag == 1)
            cout << i <<"\n";

}
}
    getch();
return 0;
}