int main(int argc, char** argv) {
const int* primes = generate_primes(10000000);
const int* last_prime = primes;
for (; *last_prime; ++last_prime);
--last_prime;
for (const int* p = last_prime; p > primes; --p) {
if (pandigital((long) *p)) {
printf("%d\n", *p);
break;
}
}
}
int
main()
{
unsigned number = 0;
for (unsigned i = 1; i <= 10000; i *= 10) {
for (unsigned t = 0; t < i; t++) {
unsigned n = form(9 * i + t);
if (pandigital(n) && n > number)
number = n;
}
}
printf("%u\n", number);
return 0;
}
int main(void)
{
uint8_t* bitmap = malloc(N / 8);
/* Find primes */
sieve(N, bitmap);
/* Loop through primes and find out if their pandigital */
int32_t i;
int32_t largest = 1;
for (i = 2; i < N; ++i)
if ((bitmap[i / 8] & (1 << (i%8))) && pandigital(i))
largest = i;
printf("%d\n", largest);
free(bitmap);
return 0;
}
int main(int argc, char *argv[]) {
std::map<int, std::pair<int, int>> products;
auto add_product = [&products](int a, int b) {
int result = a * b;
if (pandigital(a, b, result)) {
if (products.find(result) == std::end(products)) {
std::cout << a << " * " << b << " = " << result << std::endl;
products[result] = {a, b};
}
}
};
// space 1
for (int a = 1234; a <= 9876; ++a) {
for (int b = 1; b <= 9; ++b) {
add_product(a, b);
}
}
// space 2
for (int a = 12; a <= 98; ++a) {
for (int b = 123; b <= 987; ++b) {
add_product(a, b);
}
}
int sum = std::accumulate(std::begin(products), std::end(products), 0,
[](int total, const decltype(products)::value_type& data) {
return total + data.first;
});
std::cout << "#unique pandigital identities = " << products.size() << std::endl;
std::cout << "sum: " << sum << std::endl;
return 0;
}
