一亩三分地论坛

 找回密码
 获取更多干货,去instant注册!

扫码关注一亩三分地公众号
查看: 1032|回复: 1
收起左侧

Amazon OA新题 用户-好友-好友推荐的课程 code

[复制链接] |试试Instant~ |关注本帖
laonong15 发表于 2016-2-24 04:53:48 | 显示全部楼层 |阅读模式

2016(1-3月) 码农类 本科 全职@Amazon - Other - 技术电面 |Other其他

注册一亩三分地论坛,查看更多干货!

您需要 登录 才可以下载或查看,没有帐号?获取更多干货,去instant注册!

x
the original  link  is :. From 1point 3acres bbs
http://www.1point3acres.com/bbs/ ... p;page=1#pid2230193

just  write the code  by myself,  but  didnt test it :

package amazoninterview;

import java.util.Collections;
import java.util.Comparator;. from: 1point3acres.com/bbs
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;. visit 1point3acres.com for more.
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;. 1point3acres.com/bbs
import java.util.Map;

/*. 涓浜-涓夊垎-鍦帮紝鐙鍙戝竷
* 1. Use a HashSet<String> courseSet and store all the courses made by the user
2. Keep one more HashMap<Course, Integer> recommendation
2. Get the list of Friends for the user
3. Iterate through the friends list and in that find the courses selected by the friend
4. If the course present in courseSet, omit else, put it in recommendation and increment it's count by 1.
5. After all the friends are evaluated. Sort the recommendation by it's value,  

t's O(n) Space  because n is the number of courses selected in total by all your friends.
A  it would be O(k*p) where k is the number of friends and p is the number of courses a friend selects
*/
public class Recommender {

        public static void main(String[] args) {
               
        }. Waral 鍗氬鏈夋洿澶氭枃绔,
        public static Map<String,Integer> getRecommedations(String userId){
                List<String> friends = getFriendsListForUser(userId);
                HashSet<String> myCourses = getCoursesForUser( userId);
                if(friends ==null || friends.size() ==0 )
                        return null;
                if(myCourses == null)
                        myCourses = new HashSet<String>();.鏈枃鍘熷垱鑷1point3acres璁哄潧
                HashMap<String,Integer> recommendMap = new HashMap<String,Integer>();
                for(String friend:friends){
                        HashSet<String> friendCourseList = getCoursesForUser( friend);. more info on 1point3acres.com
                        for(String course:friendCourseList){
                                if(myCourses.contains(course))
                                        continue;
                                if(recommendMap.get(course)!=null){.1point3acres缃
                                        recommendMap.put(course, recommendMap.get(course)+1);.1point3acres缃
                                }
. 涓浜-涓夊垎-鍦帮紝鐙鍙戝竷                                else{
                                        recommendMap.put(course,1);. more info on 1point3acres.com
                                }
                        } 鏉ユ簮涓浜.涓夊垎鍦拌鍧.
                }
                if(recommendMap !=null && recommendMap.size() >0)
                        return sortByValue(recommendMap);
                return null;
        }
       
        public static Map sortByValue(Map unsortMap) {          鏉ユ簮涓浜.涓夊垎鍦拌鍧.
                List list = new LinkedList(unsortMap.entrySet());
         
                Collections.sort(list, new Comparator() {.鐣欏璁哄潧-涓浜-涓夊垎鍦
                        public int compare(Object o1, Object o2) {
                                return ((Comparable) ((Map.Entry) (o1)).getValue())
                                                        .compareTo(((Map.Entry) (o2)).getValue());
                        }
                });. 涓浜-涓夊垎-鍦帮紝鐙鍙戝竷
         
                Map sortedMap = new LinkedHashMap();
                for (Iterator it = list.iterator(); it.hasNext();) {
                        Map.Entry entry = (Map.Entry) it.next();
                        sortedMap.put(entry.getKey(), entry.getValue());
                }
                return sortedMap;
        }
       
        //giving function
        .1point3acres缃
        public static  List<String> getFriendsListForUser(String userId){
                return null;       
        }
        public static HashSet<String>getCoursesForUser(String userId){
                return null;
        } 鏉ユ簮涓浜.涓夊垎鍦拌鍧.
}

hopfully  it helps



daykills 发表于 2016-2-24 09:43:23 | 显示全部楼层
我面的也是这题...你后来需要搞个半小时的电话面谈吗?
回复 支持 反对

使用道具 举报

本版积分规则

请点这里访问我们的新网站:一亩三分地Instant.

Instant搜索更强大,不扣积分,内容组织的更好更整洁!目前仍在beta版本,努力完善中!反馈请点这里

关闭

一亩三分地推荐上一条 /5 下一条

手机版|小黑屋|一亩三分地论坛声明 ( 沪ICP备11015994号 )

custom counter

GMT+8, 2016-12-5 06:22

Powered by Discuz! X3

© 2001-2013 Comsenz Inc. Design By HUXTeam

快速回复 返回顶部 返回列表