算法训练 最大最小公倍数

import java.math.BigInteger;
import java.util.Scanner;

public class Main {

    public static BigInteger GCD(BigInteger a , BigInteger b){
        BigInteger gcd ;
        while( !b.equals(BigInteger.ZERO)){
            gcd = a.remainder(b);
            a = b;
            b = gcd;
        }
        gcd = a;
        return gcd;
    }

    public static BigInteger Max_GCM(BigInteger n){
        int cnt = 0;
        BigInteger mul = n;
        BigInteger j = n.subtract(BigInteger.ONE);
        while(cnt != 2){
            if ( GCD(mul,j).equals(BigInteger.ONE)){
                mul = mul.multiply(j);
                cnt++;
            }
            j = j.subtract(BigInteger.ONE);
        }
        return mul;
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner in = new Scanner(System.in);
        String str = in.next();
        BigInteger n = new BigInteger(str);
        BigInteger TWO = new BigInteger("2");
        if ( n.compareTo(TWO) == 0){
            System.out.print(2);
        }else if ( n.compareTo(BigInteger.ONE) == 0){
            System.out.print(1);
        }else if ( n.compareTo(BigInteger.ZERO) <= 0){
            System.out.print(0);
        }else{
            BigInteger max = Max_GCM(n);
            System.out.print(max);
        }
        in.close();
    }
}

#include<iostream>
using namespace std;
int main()
{
    long long n,ans;
    cin>>n;
    if(n<=2)
    ans=n;
    else if(n%2==1)
    ans=n*(n-1)*(n-2);
    else
    {
        if(n%3==0)
        ans=(n-1)*(n-2)*(n-3);
        else
        ans=n*(n-1)*(n-3);
    }
    cout<<ans<<endl;
    return 0;
}