package test;

import java.util.*;

public class test1 {

    public static void main(String[] args){

        long t1 = System.currentTimeMillis();

        System.out.println(factor(100));

        System.out.println(factor(18900));

        System.out.println(factor(72057554846356433L));

        System.out.println(factor(72057554846356487L));

        long t2 = System.currentTimeMillis();

        System.out.println("耗时：" + (t2-t1));

    }

    public static Map<Long, Integer> factor(long n){

        Map<Long,Integer> result = new HashMap<Long,Integer>();

        long t = n;

        //先处理偶数，后面处理时 i步进=2，可以节省一半时间

        while (t%2==0){

            result.put(2L,result.get(2L)==null ? 1:result.get(2L)+1);

            t = t/2;

        }

        for (long i=3;i<=Math.sqrt(t);){

            if (t%i==0){

                result.put(i,result.get(i)==null ? 1:result.get(i)+1);

                t = t/i;

            }else{

                i += 2;

            }

        }

        result.put(t,result.get(t)==null ? 1:result.get(t)+1);

        t = 1;

        //return null;

        return result;

    }

}