AcWing 1295. X的因子链
原题链接
中等
作者:
Bear_King
,
2021-02-08 16:32:11
,
所有人可见
,
阅读 239
以下均参考大佬的写法
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
typedef long long LL;
const int N = (1 << 20) + 10;
int primes[N], cnt;
int minp[N];
bool st[N];
void get_primes(int n)
{
for (int i = 2; i <= n; i ++ )
{
if (!st[i])
{
minp[i] = i;
primes[cnt ++ ] = i;
}
for (int j = 0; primes[j] * i <= n; j ++ )
{
int t = primes[j] * i;
st[t] = true;
minp[t] = primes[j];
if (i % primes[j] == 0) break;
}
}
}
int main()
{
get_primes(N - 1);
int fact[30], sum[N];
int x;
while (scanf("%d", &x) != -1)
{
int k = 0, tot = 0;
while (x > 1)
{
int p = minp[x];
fact[k] = p, sum[k] = 0;
while (x % p == 0)
{
x /= p;
sum[k] ++ ;
tot ++ ;
}
k ++ ;
}
LL res = 1;
for (int i = 1; i <= tot; i ++ ) res *= i;
for (int i = 0; i < k; i ++ )
for (int j = 1; j <= sum[i]; j ++ )
res /= j;
printf("%d %lld\n", tot, res);
}
return 0;
}