题解 | #质数因子#

#include <iostream>
#include <math.h>

using namespace std;

int main()
{
    long a;
    int i = 2;
    while(cin >> a)
    {
        if( a == 2 || a == 3)
        {
            cout << a << " ";
        }
        else
        {
            while(a != 1)
            {
                if( a % i == 0)
                {
                    cout << i << " ";
                    a /= i;
                }
                else
                {
                    i++;
                    if(i == 3)
                    {
                        continue;
                    }
                    //判断i是否为质数
                    for(int j = 2; j < i; j++)
                    {
                        if(i % j == 0)
                        {
                            //如果不是质数，那就i+1
                            i++;
                        }
                    }
                    if(i > sqrt(a))
                    {
                        cout << a << " ";
                        break;
                    }
                }
            }
        }
    }
}