【PAT】1096. Consecutive Factors

#define LOCAL
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <string>
using namespace std;

typedef long long ll;

bool isprime(int x){
    for(int i=2;i*i<=x;i++){
        if(x%i==0) return false;
    }
    if(x==0 || x==1) return false;
    else
    return true;
}

int main()
{
    #ifdef LOCAL
        freopen("data.in","r",stdin);
        freopen("data.out","w",stdout);
    #endif // LOCAL
    ll n;
    scanf("%lld",&n);
    ll sqr=(ll)sqrt(1.0*n),ans=0,len=0;
    for(ll i=2;i<=sqr;i++){
        int alen=0;
        ll res=i;
        int d=i+1;
        while(n%res==0&&res<=n){
            res*=d;
            d++;alen++;
        }
        if(alen>len){
            ans=i;len=alen;
        }
    }
    if(len==0) printf("1\n%lld",n);
    else{
        printf("%lld\n",len);
        for(ll i=0;i<len;i++){
            printf("%lld",ans+i);
            if(i<len-1)printf("*");
        }
    }
    return 0;
}