Task: Brazilian numbers
C: #include <stdio.h>

typedef char bool;

#define TRUE 1
#define FALSE 0

bool same_digits(int n, int b) {
    int f = n % b;
    n /= b;
    while (n > 0) {
        if (n % b != f) return FALSE;
        n /= b;
    }
    return TRUE;
}

bool is_brazilian(int n) {
    int b;
    if (n < 7) return FALSE;
    if (!(n % 2) && n >= 8) return TRUE;
    for (b = 2; b < n - 1; ++b) {
        if (same_digits(n, b)) return TRUE;
    }
    return FALSE;
}

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

int main() {
    int i, c, n;
    const char *kinds[3] = {" ", " odd ", " prime "};    
    for (i = 0; i < 3; ++i) {
        printf("First 20%sBrazilian numbers:\n", kinds[i]);
        c = 0;
        n = 7;
        while (TRUE) {
            if (is_brazilian(n)) {
                printf("%d ", n);
                if (++c == 20) {
                    printf("\n\n");
                    break;
                }
            }
            switch (i) {
                case 0: n++; break;
                case 1: n += 2; break;
                case 2: 
                    do {
                        n += 2;
                    } while (!is_prime(n));
                    break;
            }
        }
    }

    for (n = 7, c = 0; c < 100000; ++n) {
        if (is_brazilian(n)) c++; 
    }
    printf("The 100,000th Brazilian number: %d\n", n - 1);
    return 0;
}

C++: #include <iostream>

bool sameDigits(int n, int b) {
    int f = n % b;
    while ((n /= b) > 0) {
        if (n % b != f) {
            return false;
        }
    }
    return true;
}

bool isBrazilian(int n) {
    if (n < 7) return false;
    if (n % 2 == 0)return true;
    for (int b = 2; b < n - 1; b++) {
        if (sameDigits(n, b)) {
            return true;
        }
    }
    return false;
}

bool isPrime(int n) {
    if (n < 2)return false;
    if (n % 2 == 0)return n == 2;
    if (n % 3 == 0)return n == 3;
    int d = 5;
    while (d * d <= n) {
        if (n % d == 0)return false;
        d += 2;
        if (n % d == 0)return false;
        d += 4;
    }
    return true;
}

int main() {
    for (auto kind : { "", "odd ", "prime " }) {
        bool quiet = false;
        int BigLim = 99999;
        int limit = 20;
        std::cout << "First " << limit << ' ' << kind << "Brazillian numbers:\n";
        int c = 0;
        int n = 7;
        while (c < BigLim) {
            if (isBrazilian(n)) {
                if (!quiet)std::cout << n << ' ';
                if (++c == limit) {
                    std::cout << "\n\n";
                    quiet = true;
                }
            }
            if (quiet && kind != "") continue;
            if (kind == "") {
                n++;
            }
            else if (kind == "odd ") {
                n += 2;
            }
            else if (kind == "prime ") {
                while (true) {
                    n += 2;
                    if (isPrime(n)) break;
                }
            } else {
                throw new std::runtime_error("Unexpected");
            }
        }
        if (kind == "") {
            std::cout << "The " << BigLim + 1 << "th Brazillian number is: " << n << "\n\n";
        }
    }

    return 0;
}