primes from 1 to n c++

#include<iostream>
 
using namespace std;
   
int main(){
   
    int N, i, j, isPrime, n;
 
    cout << "Enter the value of N\n";
    cin >> N;
   
    // For every number between 2 to N, check 
    // whether it is prime number or not 
      
    for(i = 2; i <= N; i++){
        isPrime = 0;
        // Check whether i is prime or not
        for(j = 2; j <= i/2; j++){
             // Check If any number between 2 to i/2 divides I 
             // completely If yes the i cannot be prime number
             if(i % j == 0){
                 isPrime = 1;
                 break;
             }
        }
           
        if(isPrime==0 && N!= 1)
            cout << i << " ";
    }
 
   return 0;
}