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using namespace std;
typedef long long LL;
const int MAXN = 65535 + 16;
bool is_prime[MAXN];
vector<int> primes;
struct Factor {
int value;
int cnt;
Factor() {}
Factor(int value, int cnt) : value(value), cnt(cnt) {}
};
void init_prime() {
fill(is_prime, is_prime + MAXN, true);
is_prime[0] = is_prime[1] = false;
for (int i = 2; i < MAXN; i++) {
if (!is_prime[i]) continue;
primes.push_back(i);
for (long long j = 1LL * i * i; j < MAXN; j += i) {
is_prime[j] = false;
}
}
}
vector<Factor> get_factors(int x) {
vector<Factor> factors;
int temp = x;
for (int i = 0; i < primes.size() && primes[i] <= x / primes[i]; i++) {
if (temp % primes[i] == 0) {
Factor factor(primes[i], 0);
while (temp % primes[i] == 0) {
factor.cnt++;
temp /= primes[i];
}
factors.push_back(factor);
}
}
if (temp > 1) {
factors.push_back(Factor(temp, 1));
}
return factors;
}
int main(int argc, char **argv) {
init_prime();
int x;
while (scanf("%d", &x) != EOF) {
vector<Factor> factors = get_factors(x);
string ans;
for (int i = 0; i < factors.size(); i++) {
for (int j = 0; j < factors[i].cnt; j++) {
if (!ans.empty()) ans += '*';
ans += to_string(factors[i].value);
}
}
puts(ans.c_str());
}
return 0;
}
HDU 4548 1
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using namespace std;
typedef long long LL;
const int MAXN = 1000000 + 16;
struct Prime {
bool is_prime[MAXN];
int sum[MAXN];
Prime() {
fill(is_prime, is_prime + MAXN, true);
fill(sum, sum + MAXN, 0);
is_prime[0] = is_prime[1] = false;
for (int i = 2; i < MAXN; i++) {
if (!is_prime[i]) continue;
for (long long j = 1LL * i * i; j < MAXN; j += i) {
is_prime[j] = false;
}
}
for (int i = 1; i < MAXN; i++) {
sum[i] = sum[i - 1];
if (is_beautiful(i)) sum[i]++;
}
}
bool is_beautiful(int x) {
if (!is_prime[x]) return false;
int s = 0;
while (x) {
s += x % 10;
x /= 10;
}
return is_prime[s];
}
int get(int l, int r) {
return sum[r] - sum[l - 1];
}
} p;
int main(int argc, char **argv) {
int T;
scanf("%d", &T);
for (int cas = 1; cas <= T; cas++) {
int l, r;
scanf("%d%d", &l, &r);
printf("Case #%d: %d\n", cas, p.get(l, r));
}
return 0;
}