原题地址
题意:提上说的很清楚
思路:连续除就行

C++:

#include <vector>
#include<stdio.h>
#include<string.h>
#include <cstring>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <set>
#include<cstring>

#define ll long long
#define MODD 1000000007
#define pii pair<int,int>

#include<stdio.h>
#include<string.h>
//#define ll long long
using namespace std;
int main() {
    ll n,nn,sum =0, mma=0,ma=0;
    cin >>n;nn = n;
    for(ll i =2 ;i<=sqrt(n)+1;i++){
        ll j = i;
        if(nn%j!=0)continue;
        else {
            while(nn%j==0){
                nn/=j;
                j++;
                sum++;
            }//cout<<i<<" "<<sum<<endl;
            if(ma<sum){
                
                ma =sum ;
                mma = i;
            } sum=0;nn = n;
        }
    }
    if(ma==0){
        cout<<1<<endl;
        cout<<n<<endl;
    }
    else{
        cout<<ma <<endl;
        cout<<mma;
        for(ll i =1;i<ma;i++){
            cout<<"*"<<mma+i;
        }cout<<endl;
    }


}

Java:


import java.util.Scanner;
public class Main {

    public static void main(String[] args) {
        // write your code here
        Scanner sc = new Scanner(System.in);
       long n = sc.nextLong();
       long mma =0,sum =0 , ma = 0 ;
       long nn = n;
       for(long i =2;i<=Math.sqrt(n)+1;i++){
           long j = i;
           sum =0 ;
           if(nn%i!=0)continue;
           else{
               while(nn%j==0){
                   nn/=j;
                   j++;
                   sum++;
               }if(ma<sum){
                   ma = sum ;
                   mma = i;
               }
               sum =0 ;
               nn = n;
           }
       }
       if(ma==0){
           System.out.println(1);
           System.out.println(n);
       }
       else{
           System.out.println(ma);
           System.out.print(mma);
           for(long i = 1;i<ma;i++){
               System.out.print("*"+(mma+i));
           }
       }
    }
}