Task: Magnanimous numbers

C: #include <stdio.h> 
#include <string.h>

typedef int bool;
typedef unsigned long long ull;

#define TRUE 1
#define FALSE 0


bool is_prime(ull n) {
    ull d;
    if (n < 2) return FALSE;
    if (!(n % 2)) return n == 2;
    if (!(n % 3)) return n == 3;
    d = 5;
    while (d * d <= n) {
        if (!(n % d)) return FALSE;
        d += 2;
        if (!(n % d)) return FALSE;
        d += 4;
    }
    return TRUE;
}

void ord(char *res, int n) {
    char suffix[3];
    int m = n % 100;
    if (m >= 4 && m <= 20) {
        sprintf(res,"%dth", n);
        return;
    }
    switch(m % 10) {
        case 1:
            strcpy(suffix, "st");
            break;
        case 2:
            strcpy(suffix, "nd");
            break;
        case 3:
            strcpy(suffix, "rd");
            break;
        default:
            strcpy(suffix, "th");
            break;
    }
    sprintf(res, "%d%s", n, suffix);
}

bool is_magnanimous(ull n) {
    ull p, q, r;
    if (n < 10) return TRUE;
    for (p = 10; ; p *= 10) {
        q = n / p;
        r = n % p;
        if (!is_prime(q + r)) return FALSE;
        if (q < 10) break;
    }
    return TRUE;
}

void list_mags(int from, int thru, int digs, int per_line) {
    ull i = 0;
    int c = 0;
    char res1[13], res2[13];
    if (from < 2) {
        printf("\nFirst %d magnanimous numbers:\n", thru);
    } else {
        ord(res1, from);
        ord(res2, thru);
        printf("\n%s through %s magnanimous numbers:\n", res1, res2);
    }
    for ( ; c < thru; ++i) {
        if (is_magnanimous(i)) {
            if (++c >= from) {
                printf("%*llu ", digs, i);
                if (!(c % per_line)) printf("\n");
            }
        }
    }
}
 
int main() {
    list_mags(1, 45, 3, 15);
    list_mags(241, 250, 1, 10);
    list_mags(391, 400, 1, 10);
    return 0;
}





Java: import java.util.ArrayList;
import java.util.List;

public class MagnanimousNumbers {

    public static void main(String[] args) {
        runTask("Find and display the first 45 magnanimous numbers.", 1, 45);
        runTask("241st through 250th magnanimous numbers.", 241, 250);
        runTask("391st through 400th magnanimous numbers.", 391, 400);
    }
    
    private static void runTask(String message, int startN, int endN) {
        int count = 0;
        List<Integer> nums = new ArrayList<>();
        for ( int n = 0 ; count < endN ; n++ ) {
            if ( isMagnanimous(n) ) {
                nums.add(n);
                count++;
            }
        }
        System.out.printf("%s%n", message);
        System.out.printf("%s%n%n", nums.subList(startN-1, endN));
    }
    
    private static boolean isMagnanimous(long n) {
        if ( n >= 0 && n <= 9 ) {
            return true;
        }
        long q = 11;
        for ( long div = 10 ; q >= 10 ; div *= 10 ) {
            q = n / div;
            long r = n % div;
            if ( ! isPrime(q+r) ) {
                return false;
            }
        }
        return true;
    }
    
    private static final int MAX = 100_000;
    private static final boolean[] primes = new boolean[MAX];
    private static boolean SIEVE_COMPLETE = false;
    
    private static final boolean isPrimeTrivial(long test) {
        if ( ! SIEVE_COMPLETE ) {
            sieve();
            SIEVE_COMPLETE = true;
        }
        return primes[(int) test];
    }
    
    private static final void sieve() {
        
        for ( int i = 2 ; i < MAX ; i++ ) {
            primes[i] = true;            
        }
        for ( int i = 2 ; i < MAX ; i++ ) {
            if ( primes[i] ) {
                for ( int j = 2*i ; j < MAX ; j += i ) {
                    primes[j] = false;
                }
            }
        }
    }

    
    public static final boolean isPrime(long testValue) {
        if ( testValue == 2 ) return true;
        if ( testValue % 2 == 0 ) return false;
        if ( testValue <= MAX ) return isPrimeTrivial(testValue);
        long d = testValue-1;
        int s = 0;
        while ( d % 2 == 0 ) {
            s += 1;
            d /= 2;
        }
        if ( testValue < 1373565L ) {
            if ( ! aSrp(2, s, d, testValue) ) {
                return false;
            }
            if ( ! aSrp(3, s, d, testValue) ) {
                return false;
            }
            return true;
        }
        if ( testValue < 4759123141L ) {
            if ( ! aSrp(2, s, d, testValue) ) {
                return false;
            }
            if ( ! aSrp(7, s, d, testValue) ) {
                return false;
            }
            if ( ! aSrp(61, s, d, testValue) ) {
                return false;
            }
            return true;
        }
        if ( testValue < 10000000000000000L ) {
            if ( ! aSrp(3, s, d, testValue) ) {
                return false;
            }
            if ( ! aSrp(24251, s, d, testValue) ) {
                return false;
            }
            return true;
        }
        
        if ( ! aSrp(37, s, d, testValue) ) {
            return false;
        }
        if ( ! aSrp(47, s, d, testValue) ) {
            return false;
        }
        if ( ! aSrp(61, s, d, testValue) ) {
            return false;
        }
        if ( ! aSrp(73, s, d, testValue) ) {
            return false;
        }
        if ( ! aSrp(83, s, d, testValue) ) {
            return false;
        }
        
        return true;
    }

    private static final boolean aSrp(int a, int s, long d, long n) {
        long modPow = modPow(a, d, n);
        
        if ( modPow == 1 ) {
            return true;
        }
        int twoExpR = 1;
        for ( int r = 0 ; r < s ; r++ ) {
            if ( modPow(modPow, twoExpR, n) == n-1 ) {
                return true;
            }
            twoExpR *= 2;
        }
        return false;
    }
    
    private static final long SQRT = (long) Math.sqrt(Long.MAX_VALUE);
    
    public static final long modPow(long base, long exponent, long modulus) {
        long result = 1;
        while ( exponent > 0 ) {
            if ( exponent % 2 == 1 ) {
                if ( result > SQRT || base > SQRT ) {
                    result = multiply(result, base, modulus);
                }
                else {
                    result = (result * base) % modulus;
                }
            }
            exponent >>= 1;
            if ( base > SQRT ) {
                base = multiply(base, base, modulus);
            }
            else {
                base = (base * base) % modulus;
            }
        }
        return result;
    }


    
    public static final long multiply(long a, long b, long modulus) {
        long x = 0;
        long y = a % modulus;
        long t;
        while ( b > 0 ) {
            if ( b % 2 == 1 ) {
                t = x + y;
                x = (t > modulus ? t-modulus : t);
            }
            t = y << 1;
            y = (t > modulus ? t-modulus : t);
            b >>= 1;
        }
        return x % modulus;
    }

}