POJ3421：X-factor Chains——题解

#include<cstdio>
#include<cstring>
#include<iostream>
#include<cmath>
#include<algorithm>
typedef long long ll;
using namespace std;
int su[1025];
bool he[1025];
ll t[1025];
int cnt=0;
ll sum=0;
void Euler(int n){
    for(int i=2;i<=n;i++){
    if(he[i]==0){
        cnt++;
        su[cnt]=i;    
    }
    for(int j=1;j<=cnt&&i*su[j]<=n;j++){
        he[su[j]*i]=1;
        if(i%su[j]==0)break;
    }
    }
    return;
}
void fen(ll x){
    for(int i=1;i<=cnt&&su[i]*su[i]<=x;i++){
    ll p=su[i];
    if(x%p==0){
        while(x%p==0){
        sum++;
        t[i]++;
        x/=p;
        }
    }
    }
    if(x>1)sum++;
    return;
}
ll jie(int k){
    ll ans=1;
    for(int i=2;i<=k;i++){
    ans*=i;
    }
    return ans;
}
int main(){
    Euler(1024);
    ll x;
    while(scanf("%lld",&x)!=EOF){
    if(x==0)break;
    memset(t,0,sizeof(t));
    sum=0;
    fen(x);
    printf("%lld ",sum);
    ll ans=jie(sum);
    for(int i=1;i<=cnt;i++){
        ans/=jie(t[i]);
    }
    printf("%lld\n",ans);
    }
    return 0;
}