c-repl/example/primes.c

int is_prime(int num) {
    if (num <= 1) return 0;
    for (int i = 2; i * i <= num; i++) {
        if (num % i == 0) return 0;
    }
    return 1;
}

int max_prime(int limit) {
    int prime = 0;

    for (int i = 1; i < limit; i++) {
        if (is_prime(i)) {
            prime = i;
        }
    }

    return prime;
}

max_prime(250);