count number of prime numbers in a given range in c

#include <iostream>

bool is_prime(int num);

int count_primes_in_range(int start, int end);

int main() {
    int start, end;

    std::cout << "Enter the range (start and end): ";
    std::cin >> start >> end;

    int count = count_primes_in_range(start, end);

    std::cout << "Number of prime numbers in the given range: " << count << std::endl;

    return 0;
}

bool is_prime(int num) {
    if (num < 2) {
        return false;
    }

    for (int i = 2; i * i <= num; ++i) {
        if (num % i == 0) {
            return false;
        }
    }

    return true;
}

int count_primes_in_range(int start, int end) {
    int count = 0;

    for (int i = start; i <= end; ++i) {
        if (is_prime(i)) {
            ++count;
        }
    }

    return count;
}