s******d
发帖数: 424 | 1 非牛，没做过Map/reduce，只看了几篇文章，不对的请赐教
试着分析下第一题
Map按照ID partition,输出 ID Time, URL,按照 ID Time排序
Reducer接收后，对每个ID,如果和上一个Time差别小于某个值，比如10分钟，就认为为
相同访问序列，并保存最初三个URL，直到Time差别大于10分钟，重新开始计算
需要2次MapReduce，Reducer也是Mapper
Reducer的结果是三元组，再次做MapReduce。也就是再次Emit出去
Reducer2接收三元组，统计数量并维护一个最小堆，结束所有数据后将自己的TOP K输
出到文件
将所有Reducer2的输出文件读入并取最大的K个三元组得到结果 |
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Z**0
发帖数: 1119 | 2 是问你mapreduce的idea。
map, reduce, filter/emit. |
|
y****9
发帖数: 252 | 3 哎呀, 我已经尽量避免是钓鱼贴了。 我算上实习也只是入行两年一个月， 投递微软写
预期工资我只敢写92K，不敢投SDE II， 我能牛到哪里去。
“知识分子最容易犯的错误是什么？”，“往往认为讲道理是行得通的。”媳妇儿说我
就是这类。这里庆幸的是我的老板不是阿三，都是老白。 我很同意yuxrose 说的时不
我待，所以我才搬到公司附近，基本上六点半七点钟吃完饭我就可以开始上课或者看书
了。 我老板也是推荐我每半年去出外面面试一次，半年前面试了用 Ocaml 的Jane
Street， 第三轮灭了， 太多脑筋急转弯了。我们组还有每个月两天Hack Day 的福利
，也就是为啥我上面叽叽喳喳地说我有机会可以提出各种改进方案。 但有时候，也顿
足捶胸的，这头刚刚写完federation，回头发现最新版的Windows Server 2012 的AD就
已经有了Federated Service。 再提出要改的时候，产品已经到了QA。 这种也就是我
经验不足，研究没做足导致的。
我后来也和一些朋友聊，除了自己学习， 他们鼓励我多交流，写博客，答题，混沙龙
。 我觉得也有道理。 负能量有点多了 ... 阅读全帖 |
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b**********5
发帖数: 7881 | 4 You are writing a simulation for a print server. This print
server can accept jobs from 3 places - network, USB, or operator. It can
dispatch only one job at a time. Each input job should contain an integer t
which is the time in seconds it will take to process the job. Write a multi-
threaded program to simulate the server and provide some simulated load with
jobs. Think, of some interesting statistics your program should emit and
code them in. |
|
b**********5
发帖数: 7881 | 5 map reduce我也知道啊， 但这个particular问题， 我不大懂
比如你现在有很多log， 这log里是tweetID为key， 然后event就算view过一次吧, 然
后每个event还提供一个timestamp
这个getSequence(key, start, end, day/hour) 是算什么？ 是算每个hour，这个
tweet被view过多少次？
你这个functionality怎么算？ 这个map reduce， map 是emit（key， （1，
timestamp)) pair， reduce成什么？ 你仔细说说。。。
我觉得这里问问题， 很多人就说个general concept， map reduce， 我也知道啊，
但你说说细节看。 interview时， 说细节还是很容易fail的。 头一晕， 就全都混
掉了 |
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r******9
发帖数: 566 | 6 我面的是前端职位，所以很多前端的问题，但是算法题也有很多。lc才刷到70多道的菜
逼飘过。
电面：一大堆html css angular的东西。算法题的话他问了一个：给你100万个数，怎
么选出前100大？维护size为100的heap。
onsite：全算法。
第一个人国人大哥，出了两道题：
第一题：
问我懂不懂SQL？我当时想我要是说不懂会怎么样，毕竟数据库忘的差不多了。后来我
还是说懂，然后他出了一道题：给出一张表，有id，有score。让你选出这张表，score
第二大的id.
我知道这题是子查询做的。但是还是他提示下才做出的。好像是这样：select id, max
(score) from table where score != select max(score) from table.
然后他又问，这样的子查询，时间复杂度是多少？我看了一下说是2n。所以是n 好像对
了。
他又问你懂基本排序么？快排归并什么的时间复杂度？我就说了一下。 然后进入第二
题。
第二题：
问有多少可以走通的路劲？
J1:{},
J2:{J1,J4}
J5:{J3,J6,J2,J4}
J4:{... 阅读全帖 |
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c******w
发帖数: 1108 | 7 Map reduce吗？
Map
For every node x, for every y, z in x's neighbor list
Emit ((y,z),x), ((z,y),x), ((x,y),-), ((x,z),-)
Reduce
For every key (y,z), among the values
1. If there exist both - and x, then (x,y,z) is a triangle for Q1
2. If there exists at least one x and no -, then (y,z) is a pair for Q2 |
|
g*****g
发帖数: 34805 | 8 所以你这傻逼根本不能想象这种scale的系统怎么写出来的，为什么要抓这么多的数据
。这是我们官方blog的文章
，两年以前的，我们用户数比两年前接近翻倍。你丫还能再傻逼一点吗？
http://techblog.netflix.com/2013/12/announcing-suro-backbone-of
They collectively emit more than 1.5 million events per second during peak
hours, or around 80 billion events per day.
别忘了我老没出来吹，是你小装逼被我打脸，扛不住了非要扯到我们公司上。我老公司
没人FG数据量大没错，秒杀你们银行是妥妥的。你丫有种拿你们公司出来比，别成天扯
人F大旗，感情F不在硅谷在花街吗？ |
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s*****r
发帖数: 43070 | 9 第二题应该是MapReduce的经典，mapper 完了run combiner，先filter掉chunk 里面不
unique的，reducer 只emit single element的input list
第一题貌似答反了，C*有row locking，是consistency的，但只能是row consistency
第三题应该是每个node过段时间就去zookeeper上create一个，这种node有lifetime，
过一段时间消失，monitor看哪个node没有register就好了
partition
point
namenode
data |
|
r********k
发帖数: 258 | 10 For the first extension, the solution is correct. For the second option,
here is one way to do it:
1. find min and max of the array;
2. check if condition is met; if so, stop.
3. if condition is not met, split array into three:
from min to max, and left over two min_leftover, and max_leftover.
4. repeat step 1 and step 2 for three arrays.
5. emit -1 if all recursions end without meeting the condition. |
|
e*********g
发帖数: 323 | 11 Post-Doctoral Fellow on Spintronics in the Department of Electrical and
Electronic Engineering, The University of Hong Kong
Applications are invited for appointment as a Post-Doctoral Fellow (PDF) on
spintronics in the Department of Electrical and Electronic Engineering, from
as soon as possible for initially one year with the possibility of renewal.
Candidates should possess a doctoral degree in Physics, Materials Science,
Electrical Engineering, or a related discipline, with background in
theo... 阅读全帖 |
|
t********7
发帖数: 2 | 12 Job Title
Research Scientist
Location
New Haven, CT 06511 US (Primary)
Application
Email to [email protected]
/* */ Job Description
Company:
Saphlux is a venture backed start-up company commercializing an innovative
semi-polar LED (light-emitting diode). Semi-polar orientation has been well
proven to address long- standing droop and efficiency problems of convention
LEDs. The commercialization of this technology will bring revolutions to
many LED applications starting with general lighting... 阅读全帖 |
|
C*******d
发帖数: 15836 | 13 Pressure treated woods have chemicals harmful to people. You need special
care even to just cut or touch them, not to say burn. They can emit harmful
gas and leave harmful chemicals in the chimney, which is definitely not what
you want. |
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g*****9
发帖数: 4125 | 14 No, if you use regular paint, it will emit Formaldehyde, which is one kind
of Volatile Organic Compounds (VOCs), it will irritates the mucous membranes
and can make a person irritated and uncomfortable.
If you can not leave your window open for a while or have a mechnical air
exchange running all the time, do not put your baby in the room/house that
was just painted, it can contribute to what is called "sick building
syndrome". Especially babies, I am not kidding.
If you used the paints I sugges |
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g*****9
发帖数: 4125 | 15 In short, the term "Chinese Drywall" (or tainted drywall or wallboard)
refers to drywall imported from China from 2001 to 2007 which contains
contaminants that are emitting gases which usually (but not always) create a
noxious odor and corrode copper and other metal surfaces, thereby damaging
your air conditioner, electrical wiring, copper plumbing, appliances and electronics.
Symptoms typically appear in about 24 months. Corrosion of electrical
wiring can hamper the effectiveness of your sm |
|
m**********2
发帖数: 6568 | 16 you can spend a lot of money and emit a lot of CO2 to power-wash the white
roof 3 times a year. hehe. |
|
d****9
发帖数: 58 | 17 How about the health concern caused by the UV light emitted by the CFL? |
|
d****9
发帖数: 58 | 18 How about the health concern caused by the UV light emitted by the CFL? |
|
a**********t
发帖数: 9684 | 19 Laptop and cell phone don't emit radon |
|
z****9
发帖数: 69 | 20 friends, I am working at sourcing department at IKEA and I know exactly
where IKEA bought these mattress and how it comparing to the U.S retailers,
say sealy, simmons etc.
first, when you say quality, let me ask you several things. All foam using
at IKEA mattress has been tested to be sure free of lead, flame retardant,
antimony, tinorganic, phalates, etc. No one at Sealy and Simmon did that. If
you go to IKEA and asked for these report, then ask them to call IKEA
trading at 7132630689 and I wil... 阅读全帖 |
|
p******t
发帖数: 3764 | 21 幸亏没下单，去amazon上看了下review, 有人比较了几个steam mop
贴上来给大家看看
最后决定买ereka的enviro steamer
(update: This review was updated on 11-2-09 after I got to compare the
Bissell as well as add notes about the Ladybugg steamer at the bottom)
I live in a neighborhood where EVERY home is "green built certified" this
means that, to have that certification, the builder built no homes with
carpet. All the main floors are polished concrete and the upper floors wood.
The bathrooms all have tile and/or slate in every home.
Be... 阅读全帖 |
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m***y
发帖数: 14763 | 22 The second one seems like a cell tower, no high voltage.
Again, one could argue it actually emits more radiation :) |
|
o****n
发帖数: 348 | 23 辐射有一定危害性(UV)，不过频段跟高压线差太远了。 另： 低色度导致致癌是从哪来
的？
跟这两个比，辐射最大的应该是手机。
From Wiki:
Human health
Main article: Fluorescent lamps and health
According to the European Commission Scientific Committee on Emerging and
Newly Identified Health Risks (SCENIHR) in 2008, CFLs may pose an added
health risk due to the ultraviolet and blue light emitted. This radiation
could aggravate symptoms in people who already suffer skin conditions that
make them exceptionally sensitive to light. The light produced by some
sing... 阅读全帖 |
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M***y
发帖数: 81 | 24 yes. This is probably transmission line of 66kv and above. contact your
local utility company and they can perform a free EMF for you. Typically the
higher the line, less emitting.
Good Luck |
|
F***Q
发帖数: 6599 | 25
it sounds a lot, but seriously, it is not much at all
based on a report from a biased source:
http://www.marble-institute.com/pdfs/truthaboutgraniteradonradi
"the amount of radon gas emitted by a granite countertop is less than one
millionth of that already present in household air from other sources."
believe it or not, it is up to you |
|
y***j
发帖数: 11235 | 26 这种卖石头的协会肯定不会自砸饭碗。
http://www.nytimes.com/2008/07/24/garden/24granite.html?pagewan
“But with increasing regularity in recent months, the Environmental
Protection Agency has been receiving calls from radon inspectors as well as
from concerned homeowners about granite countertops with radiation
measurements several times above background levels.”
"Research scientists at Rice University in Houston and at the New York State
Department of Health are currently conducting studies of granite widely
used ... 阅读全帖 |
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a*****0
发帖数: 3319 | 27 granite emits radon and gamma radiation. Most granites' radiation is
negligible compared to the environmental radiation. But some granites'
radiation is relatively high, especially those with pink color and flowing
pattern. You can request a test at the granite shop. |
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h********5
发帖数: 386 | 28 http://www.sciencedaily.com/releases/2012/07/120718122738.htm
"Our study revealed that the response of healthy skin cells to UV emitted
from CFL bulbs is consistent with damage from ultraviolet radiation"
---------------------------------------
I changed most used ones from CFL to LED. CFL has some negative health
impact. |
|
t*****e
发帖数: 15794 | 29 看篇好文
March 21, 2013, 3:15 pm 285 Comments
Addressing Fears About LED Light Bulbs
In my Times column Thursday, I reviewed a new generation of LED light bulbs.
They last 25 times as long as regular bulbs, use maybe one-eighth the
electricity, work with dimmers, turn on instantly to full brightness and
remain cool to the touch. A big drawback has always been cost, but now, I
noted, the prices have fallen.
This column generated a lot of reader e-mail, probably because LED
represents change. And chan... 阅读全帖 |
|
j****i
发帖数: 68152 | 30 很解气啊。
Chinese drywall causes a stench.Drywall imported from China last decade, and
installed in an estimated 100,000 homes in the U.S., turned out to be a
stinker.
Result: It emitted sulfurous gas that gave off a rotten egg smell and
corroded wiring, air conditioning units, and electronic appliances. It also
caused homeowners to be sick. |
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r***o
发帖数: 3058 | 31 搜索了下， 果然 这些都是 标准
马桶 1.6加仑 或一下， 水龙头 2.2 gpm 或以下， 淋浴头 2.5 gpm 或以下。
(c) “Noncompliant plumbing fixture” means any of the following:
(1) Any toilet manufactured to use more than 1.6 gallons of water per flush.
(2) Any urinal manufactured to use more than one gallon of water per flush.
(3) Any showerhead manufactured to have a flow capacity of more than 2.5
gallons of water per minute.
(4) Any interior faucet that emits more than 2.2 gallons of water per minute.
(e) “Water-conserving plumbing fi... 阅读全帖 |
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s**********h
发帖数: 436 | 32 Change the carpet! If the smell is strong enough for you to detect it, then
it's emitting a lot of chemicals. It can cause cancer, especially for young
kids. That's why I'd prefer old carpet to new low quality carpet. If you don
't do anything till 明显的身体健康变化 occurs, then it's TOO late. |
|
x****u
发帖数: 12955 | 33
Exposure to Gamma radiation is fundamentally different than contain
contaminant that emits Gamma radiation.
How would you like to be "disinfected" all the time? |
|
n***s
发帖数: 10056 | 34 Now onto cons:
1. humming sound -- some high power LED has low humming sound.
2. emits EMF
3. color index may not be as good
4. cost still a bit high
5. brightness fades after a couple of years
6. may use more energy than marked on package -- in one guy's test, an LED
bulb drew 10 times more energy than what's listed on its box. |
|
D******D
发帖数: 1022 | 35 if your card has blink function. they actually emit radio wave about your
card function, it is very easy to be captured
somebody just ring the machine to walk around in the mall to capture these
information.
A simple credit card cover can solve this problem |
|
z****l
发帖数: 5282 | 36 ☆─────────────────────────────────────☆
natura (那图拉) 于 (Tue Sep 20 15:51:25 2011, 美东) 提到:
前天看到Discover上有一笔1300多刀的charge
打给客服，说是在离家30麦的一家Granite Marble store刷卡消费的
可是卡明明一直在我钱包里，不知道怎么刷的
昨天顺便检查钱包里另一张Chase Freedom, 通常用来买菜用的
惊讶的发现从8月底开始，每天都有一笔加油站的消费，都是$120左右
近30天来一共刷掉了$3500左右
打给客服，说是在离家60麦开外的几家油站(Chevron, Exxon, Shell, etc)刷卡的
赶快检查钱包里其他几张卡，貌似尚未中招。
网上盗用卡号还好理解，这两张卡明明一直在我钱包里
怎么能够physically刷卡呢？
难道骗子能够复制信用卡？
大家说说
☆─────────────────────────────────────☆
canhelp2007 (Tomorrow) 于 (Tue Sep 20 15:55:36... 阅读全帖 |
|
t****n
发帖数: 324 | 37 Parents need to pay attention to this:
Made of PVC Foam (Phthalate Free)
PVC Foam definitely emits poison fume. |
|
i*****t
发帖数: 24265 | 38 yes.
The microwave has metal cover, but 电磁炉 directly emit the wave to outside.
The safest way is to keep far away from the working microwave oven or let
other family member use the oven
BTW, did you measure the wireless network of laptop? I'm very curious about
that.
0. |
|
|
T******1
发帖数: 158 | 40 From: Laser Dermatology by Christine C.Dierickx/David J. Goldberg
The management of giant congenital melanocytic nevi (GCMN) remains difficult
. It has been well proved that there is an increased risk of malignant
changes among patients with these lesions, although the amount of increased
risk for each individual patient is not clear.
Removal of superficial nevus cells is possible by dermabrasion, curettage,
shave excision, or laser. High energy CO2 laser therapy is less traumatic
and can produc... 阅读全帖 |
|
b****t
发帖数: 153 | 41 futon matress，直接铺地上
没用过memory foam的床垫，记得听说memory foam 会emit有害化学成分，对大人都不
甚健康，买的话要慎重 |
|
B*W
发帖数: 1341 | 42 这事儿不是n多人普及过n多回了么？
The following question was answered by an expert in the appropriate field:
Q
I'm pregnant and I have to use computers for a few hours a day and I know
electric appliances also emit radiation. How harmful is all of this to me
and my baby?My friend suggests that I buy radiation protection suits.
According to their advertisements, the garments are made from a kind of
fiber interwoven with antiradiation material. Do you think it works? Should
I wear it?
问题：我现在怀孕了，每天需要用电脑几个小时，我知道电器也... 阅读全帖 |
|
B*W
发帖数: 1341 | 43 这事儿不是n多人普及过n多回了么？
The following question was answered by an expert in the appropriate field:
Q
I'm pregnant and I have to use computers for a few hours a day and I know
electric appliances also emit radiation. How harmful is all of this to me
and my baby?My friend suggests that I buy radiation protection suits.
According to their advertisements, the garments are made from a kind of
fiber interwoven with antiradiation material. Do you think it works? Should
I wear it?
问题：我现在怀孕了，每天需要用电脑几个小时，我知道电器也... 阅读全帖 |
|
s*********s
发帖数: 70 | 44 唉，总是挑骨头，感冒大疫苗会死人？你问医生他也不敢这么说。
ANDY
Dear Thinktwice,
My son, Andy, was born June 16. He was healthy and full term. He had his
first shot on August 18. He started screaming right away and continued to
cry. He screamed and cried for the next few days, except when he fell into a
deep sleep. Also, when he was awake, he now had a glassy, odd look in his
eyes, as though he was looking right past us. He just wasn't right.
I took him to the Emergency Room where I was told he was having 'a bad day.'
I ask... 阅读全帖 |
|
c*******k
发帖数: 1308 | 45 Prefinished solid wood floor is the most healthy floor for kids. Even with
engineered wood, there are brands that are GreenGuard certified, meaning
they won't emit VOC. |
|
S******n
发帖数: 3 | 46 A graduate research assistant position in optoelectronics and nanophotonics
is available in EECS department at case western reserve university.
Successful candidate will be working with Dr. Hongping Zhao in the area of
designing novel optoelectronic devices including light-emitting diodes and
solar cells.
Candidates should have strong motivation in the research areas of photonics
and optoelectronics applied for energy efficiency and renewable energy.
Previous experiences on the following fields ... 阅读全帖 |
|
s***n
发帖数: 2366 | 47 Why Does Broccoli Smell so Bad?
Answer
Broccoli smells bad because the vegetable contains hydrogen sulfide. When
you cut the broccoli, it emits small amounts of the gas. The smell is even
stronger, and stinkier, when you cook the vegetables. |
|
s***n
发帖数: 2366 | 48 Why Does Broccoli Smell so Bad?
Answer
Broccoli smells bad because the vegetable contains hydrogen sulfide. When
you cut the broccoli, it emits small amounts of the gas. The smell is even
stronger, and stinkier, when you cook the vegetables. |
|
k*****y
发帖数: 2069 | 49 还以为玉米最安全了，结果也不行，olive oil炒菜好像很不行？！
Poisonous Foods!! What the major Health Food Stores are not telling you
about the safety of their health foods.
The Dangers Of Using Canola Oil
Recently I bought cooking oil that's new to our Health Food Stores and
Supermarkets, Canola Oil. I tried it because the label assured me it was
lowest in "bad" fats. However, when I had used half the bottle, I concluded
that the label told me surprisingly little else and I started to wonder:
Where does canola oil come... 阅读全帖 |
|
r******g
发帖数: 22 | 50 We are looking for a postdoc with experience in synthetic organic
chemistry or related discipline. Previous experience with handling
radioactive PET or SPET radiopharmaceuticals for preclinical and/or
clinical application would be an advantage, but are not required.
Duties will involve the development, synthesis and evaluation of novel
PET probes labelled with short-lived positron emitting radioisotopes(C-
11,F-18) for molecular imaging.
if you are interested in, please contact with me by email:... 阅读全帖 |
|
