poj 3421 X-factor Chains(分解质因数+组合数学)

幂和的阶乘/幂阶乘的和

#include<stdio.h>
#include<string.h>
#define ll long long
ll j[25];
void ini()
{
j[1]=1;
for(ll i=2;i<=20;i++)
j[i]=j[i-1]*i;
}
int main()
{
ini();
ll n;
while(scanf("%lld",&n)!=EOF)
{
int ans=0;
ll b=1;
for(ll i=2;i*i<=n;i++)
if(n%i==0)
{
int cnt=0;
while(n%i==0)
{
cnt++;
n/=i;
}
ans+=cnt;
b*=j[cnt];
}
if(n>1) ans+=1;
printf("%d %lld\n",ans,j[ans]/b);
}
return 0;
}