31 lines
745 B
C++
31 lines
745 B
C++
#include <iostream>
|
|
#include <cmath>
|
|
|
|
using namespace std;
|
|
// 欧拉筛
|
|
const int N = 1e5 + 10;
|
|
int primes[N], cnt; // primes[]存储所有素数
|
|
bool st[N]; // st[x]存储x是否被筛掉
|
|
void get_primes(int n) {
|
|
for (int i = 2; i <= n; i++) {
|
|
if (!st[i]) primes[cnt++] = i;
|
|
for (int j = 0; primes[j] * i <= n; j++) {
|
|
st[primes[j] * i] = true;
|
|
if (i % primes[j] == 0) break;
|
|
}
|
|
}
|
|
}
|
|
int main() {
|
|
int n;
|
|
cin >> n;
|
|
get_primes(sqrt(n));
|
|
for (int i = 0; i < cnt; i++) {
|
|
while (n % primes[i] == 0) {
|
|
cout << primes[i] << endl;
|
|
n /= primes[i];
|
|
}
|
|
}
|
|
if (n > 1) cout << n << endl;
|
|
|
|
return 0;
|
|
} |