i**********e
发帖数: 1145 | 1 这道题 FB 面试有人贴过，而且听说代码写起来很麻烦.
在网上尝试找关于 Dutch National Flag Problem (DNFP) 的扩展至 k 种颜色的解法
，找了老半天都没找着（连四种颜色的也没找到），代码只好自己写了.
今天写 DNFP 四种颜色排序基本写对了，但是某些 test cases 不能通过。主要难度在
于当此颜色为第一颜色的时候应该怎么交换。研究了老半天，终于开窍了。原来是忘掉
了一个很重要不变量（invariant），就是 0 <= r <= w <= b < n （这里指的是原题
的三种颜色，r=red, g=green, b=blue，扩展至 k 种颜色的不变量为 0 <= mid[0] <=
mid[1] <= ... <= mid[k-1] < n）.
DNFP 四种颜色写对了之后，思路就清晰了，非常容易扩展至 k 种颜色。利用一个内循
环，来保持不变量 0 <= mid[0] <= mid[1] <= ... <= mid[k-1] < n. 这内循环似乎
很耗时，但少了这内循环，我又不知道怎样才能保持以上的不变量，望高手指教.
顺便介绍一个写... 阅读全帖 |
|
x*******5
发帖数: 152 | 2 请教各位大牛一个问题：
Problem: Output all subsets of size of m from an array
Solution Hints: String permutation Problem variant
Python Codes:
def Subset_m(v,l,m,output):
"Find all subsets of an array v of size m, need fixing"
if l==m:
print output
return
for i in range(l,len(v)):
output[l]=v[i]
Subset_m(v,l+1,m,output)
C++ Codes:
/*Description: output all the subset of size m
Input:vector v, int m,int l, vector& output
Output: void
*/
... 阅读全帖 |
|
c**********e
发帖数: 2007 | 3 In an exam you have n problems to work on. i=0, 1, ..., n-1.
The i-th problem takes you x[i] minutes, and give you a score s[i].
You have 60 minutes to work on them. How can you get the best score? |
|
c**********e
发帖数: 2007 | 4 Assumptions:
1. You do not get partial credit on a problem.
2. If you spend x[i] minutes on i-th problem, you will get the s[i] points. |
|
D********g
发帖数: 650 | 5 /**
* In an exam you have n problems to work on. i=0, 1, ..., n-1.
The i-th problem takes you x[i] minutes, and give you a score s[i].
You have 60 minutes to work on them. How can you get the best score?
*/
static class DPElement {
int value;
int prevCostIdx; // 0-based cost idx
int takenThisElement; // 0/1, indicating whether taking current
element, idx 0 based.
public DPElement() {
value = 0;
prevCostIdx = 0;
tak... 阅读全帖 |
|
c***x
发帖数: 455 | 6 Hi guys，
看到job description 里面有一条 understanding of triaging problems.
什么是triaging problems？懂的兄弟姐们能否给个big map或者链接？谢谢！ |
|
b*******e
发帖数: 217 | 7 this is a DP problem.
SPath(S, V, K) = Min(SPath(S, Parents of V, K-1) + W)
this is called shortest reliable path problem. |
|
j*d
发帖数: 96 | 8 NP-complete is itself a set, not a method.
Reduction is a method of making a problem with known complexity a subroutine
of the problem you want to solve. |
|
B*******O
发帖数: 543 | 9 Latest updated, pictures in following links:
Any feedback will be appreciated.
I talked to my inspector, he said that he does not suggest to hire a structure engineer. What do you guys think by looking at the cracks?
Driveway cracks
Garage wall cracks
Inspector claims that the old house that I am buying is having settling
problem.
The south and east sides are ok with 0.4-0.5% settling
The north and west sides have problem with 0.8-0.9% settling
if>1%, foundation will need to be repaired.
However |
|
k******o
发帖数: 3328 | 10 Agree. Even agent B say "no problem", it does not mean "no problem" at all.
There is law and regulation to govern this kind of issue. |
|
z****e
发帖数: 555 | 11 Hi, I signed up for FIOS and the Verizon technician came to the house and
installed the service. He drilled hole on the outside of the wall and pulled
the cable from outside to inside. I asked him to put the temporary cable on
one side of the house (which goes through bushes), he agreed. Everything
seems working OK.
The next day, another team came (they are the Verizon contractors, a
differrent company) installed underground pipes on my lawn. He also
installed a box on the outside of the wall. S... 阅读全帖 |
|
G***G
发帖数: 16778 | 12 garage door remote has a problem.
I have to press 10 times to get it work.
I have tested different remote, they have the same problem.
how to fix it?
thanks. |
|
l**********r
发帖数: 240 | 13 Health - Reuters
B-Vitamin Problems May Cause Depression in Some
By Alison McCook
NEW YORK (Reuters Health) - New findings suggests that some people with
depression might have problems metabolizing the B vitamin folate -- supporting
the idea that supplements could help ward off the condition, researchers say.
Investigators in Norway found that depression occurred more commonly in people
who had high levels of the amino acid homocysteine in their blood, and in
those who carried a form of a gene t |
|
w*********s
发帖数: 2136 | 14 【 以下文字转载自 Parenting 讨论区 】
发信人: whiteclouds (/ 参考消息 /), 信区: Parenting
标 题: The Problem Of Pathogenic Vaccine Contamination
发信站: BBS 未名空间站 (Fri Sep 17 07:13:12 2010, 美东)
What Is Coming Through That Needle?
The Problem Of Pathogenic Vaccine Contamination
By Benjamin McRearden
DrCarly.com
12-14-2
In recent times mankind is experiencing a situation never previously
encountered, that being the threat of release of pathogens intended to kill
or disable large numbers of people. That danger has prompted |
|
j****i
发帖数: 496 | 15 Help - I live a very healthy lifestyle, yet in the past 6-12 months, I've
had a random variety of problems:
Very high cholesterol
Abnormally low WBC
Chronic fatigue
Hair loss
Unexplained weight gain
Frequent infection / inflammation
Sudden high fever without any other symptoms
Newly developed food and insect allergy
Irregular bowl movements
...
I am so tired of trips to doctors and all the prescriptions given to me that
only target each individual symptoms during acute attacks. I would like to
... 阅读全帖 |
|
f****o
发帖数: 2770 | 16 marrow bipsy sounds scary but it's frquently done for patients with
hematologic problems. you will receive lidocaine to numb the area. it's a
easy procedure with some soreness after it's done.
it can be used to check all kinds of hematologic problems, aplastic anemia,
myelodysplastic syndrome, chronic/acute myeloid/lymphocytic leukemia, etc.
maybe you should see a hematologist |
|
f********i
发帖数: 8412 | 17 I got either a "Service is not available. Please try again later." message,
or a message as shown below:
Your order attempt failed. Possible reasons include:
• The billing information that was entered does not match the
billing information for this card.
• Your credit card number or expiration date is invalid.
• The credit card security code that was entered is invalid.
If you try again and still cannot complete your order, you may need to
contact your issuing bank. Yo... 阅读全帖 |
|
m**2
发帖数: 3374 | 18 Recently when I tried to log into my netspend/brinks accounts, the system
always asked me three security questions. After I finished answering them,
the "Next" button on the screen was disabled and I could not go further
except for clicking the Log Out button. But after logging out, I could not
log back in anymore and apparently the online access was blocked. Had to
call netspend/brinks to unblock and it is very time consuming. It happened
three times already. Was wondering if they have a bug in... 阅读全帖 |
|
f********e
发帖数: 1298 | 19 OS X 10.10.4
Safari
No problem
mint connection no problem as well |
|
e***a
发帖数: 1982 | 20 ios app no problem
mac osx Yosemite with chrome no problem
start clean (clear cache, cookies etc) and try again?
security |
|
|
W***0
发帖数: 83 | 22 Does anyone has uterus drop. Problem after giving birth? How do you guy get
it fix? It is a very frustrated problem. |
|
s**t
发帖数: 4 | 23 推荐一本书 - solve your children's sleep problem
Solve Your Child's Sleep Problems: New, Revised, and Expanded Edition
是医生推荐的，也是有朋友推荐的。
照着书上说的进行了TRAINIG,现在总算可以睡好了。当然夜里11点和5点还要喂俩次，
关键是入睡没有那么痛苦了 |
|
f*****x
发帖数: 36 | 24 I am looking for more math word problem or problem solving questions for my
son to practice. Any one have any suggestion? Thanks a lot. |
|
l*********8
发帖数: 254 | 25 家有5岁男宝，活泼，好动，爱说话。老人待回中国2年多，4岁回来。
刚回来的时候不讲道理，不听话，脾气极差，摔东西打人，说话声音很大。说话做事情
完全不顾及周围人的感受，我行我素，很固执。
经过一年的改造，基本讲道理，听话了，自己洗澡，刷牙，收拾Bedroom和gameroom。
自己叠被子。在商店帮大人推购物车，帮忙拿shopping bag回家。吃完饭后自己收拾碗
筷，擦桌子，洗碗，洗锅。帮忙做饭，看锅。看到scooter脏了，自己会清洁。酷爱读
书：从刚回来的一个英文不认识到自己基本能读Level 2.
但是小娃底气还是很足，说话声音还是很大（大人提醒后会变小；一会儿又大了）。有
的时候，大人跟他说话的时候他不看着大人，也不理大人。大人说话的时候喜欢插嘴。
玩tic-tac-toe或是cards，只能赢不能输，输了就赌气说“I NEVER WIN”, "I DO NOT
LIKE THE GAME, BECAUSE IT IS BORING...."有的时候跟小朋友相处的时候觉得他不
太合群（尤其是别的小孩玩ipad 和其他的video game；我们从来不给他玩video gam... 阅读全帖 |
|
l**a
发帖数: 5175 | 26 We don't have any that kind of problems, no cavity, no significant problems.
Her teeth are almost perfect, just little gaps between her lower bottom
teeth.
That's because her teething too early, hopefully, that could be done. |
|
m*****t
发帖数: 239 | 27
新加坡数学的Challenging Word Problems据说是比同系列的textbook和workbook略难
半个到一个年级
Challenging Word Problems的一个特别之处是这个系列会教孩子画一种横杠的图来代
表各个数字，用来解题，这种办法是用来替代基本代数中变数的概念的，同时也是为代
数作准备。不过个人觉得，这个系列到了五六年级的那两本，里面的题目比较复杂，又
努力避免引入代数中的概念，实际上在解题方式上有点刻意绕弯子了，未必有太大益处
。尤其是对于抽象思维比较好的孩子，到这个阶段，还不如直接教一点代数方程的概念
好了 |
|
|
s***n
发帖数: 1280 | 29 我觉得这本书适合那些备考AIME及USA(J)MO的孩子或是对从事数学相关专业感兴趣的孩
子，不太适合那些针对SAT或是AMC 10/12的孩子。
AOPS的系统教科书厚是因为它要从零讲起，不仅要讲解很多基础知识点，还要涵盖竞赛
知识点和解题技巧。另外，AOPS的竞赛备考书主要涵盖竞赛知识点和解题技巧，基础知
识点最多只总结下，并不厚。
Zeitz的ACOPS并不是传统意义上的数学教科书，或是竞赛备考书。它主要不是传授具体
的解题技巧，而是训练抽象的解题思维和能力 - 当你碰到一个以前没见过的题型时，
如何去找到解法。这些方面的训练对解决AIME难题或USA(J)MO题有帮助。
要真正理解和掌握ACOPS里的解题思维，需要有一定的解题能力和底子。很多备考AMC的
孩子还不到这个水平。我觉得还是AOPS的书更适合他们。
ACOPS自介：
"This is a book about mathematical problem solving for college-level novices
. By this
I mean bright people who know some mathe... 阅读全帖 |
|
t******l
发帖数: 10908 | 30 我觉得你说的确实有道理。但另一方面，我不是拿 Zeitz 的 ACOPS 当数学教科书
或者备考书用的，我其实是把那玩意儿当数学兴趣书用。具体这么说：
首先对普通初中娃娃的一个问题，并不是咋学数学或者拿个高分，而是我为啥要学
数学，以及超过学校课堂要求的数学？（sense of purpose）。。。当然这个对我
家娃比较简单一些，我娃数学课堂成绩比较她旁边的娃娃们都差一些，所以毕竟 AMC
上面有可能找回点场子，也对将来高中数学多点信心。
（当然前提也是初中阶段，没有高中要切实分数的迫切要求，所以也有相当的自由度）。
然后第二个问题就是，在知道了解切实有用基本概念，我为啥要学那些无聊的特么
一辈子可能都用不上的定理/办法？。。。这个理由就好比小娃要想玩有点意思的
chess end-game puzzle，那基本的玩意儿都多少得知道一点不是？当然 chess
end-game puzzle 也没啥用，但是对小娃也是好玩不是？。。。但话是这么说，实际
上娃不可能听了话就会照办。。。所以大部分酱油 chess 学校（不是要正规比赛上
棋谱的正规竞赛型 chess 学校）就先上有些趣味 e... 阅读全帖 |
|
t******l
发帖数: 10908 | 31 当然第四第五公理，三角形内角和是 180 度，或者勾股定理这些，就不一定需要从
puzzle problem 入手。。。因为那是对空间形状的基本认知，属于基本的好奇心
范畴。。。而且不学会的话，这连学校考试都不行。。。但稍微复杂一些的还是
需要一定的 puzzle problem 拉动，这样可以一定程度对抗大部分普通娃浅尝辄止
的天性。 |
|
b***t
发帖数: 59 | 32 【 以下文字转载自 Mathematics 讨论区 】
发信人: brout (brout), 信区: Mathematics
标 题: F-test for regression problems的参考文献求助
发信站: BBS 未名空间站 (Sun Feb 10 21:15:33 2013, 美东)
F-test的wiki里面有一段讲到了Regression problems，但是没有给出参考文献。
谁知道哪本书或者文献里有相关信息吗？书的话最好是有电子书我可以直接看。
文献的话有pdf文档最好了，或者给我期刊，年份，作者，页码也行。 |
|
s**m
发帖数: 1564 | 33 i ordered multiple items in one order. one of them is store pickup and the
rest are shipped to my address. after I picked up the one, OO TRU showed
merchant confirmation check however the order amount is of only partial pick
-up order. now I can not sumit order info. What to do? Wait for rejection
and then report problem?
have you guys seen such problems and how did you solved it?
Thanks |
|
w**********l
发帖数: 8501 | 34 【 以下文字转载自 Military 讨论区 】
发信人: desesperado (Estoy), 信区: Military
标 题: 奥巴马: "Our problems are solvable"
发信站: BBS 未名空间站 (Mon Aug 8 14:40:54 2011, 美东)
http://www.cnn.com/2011/POLITICS/08/08/obama.economy/index.html
President Barack Obama offered a reassuring assessment of the U.S. economic
situation Monday, calling the country's problems "imminently solvable"
despite last week's downgrade of its credit rating by Standard & Poor's.
The president also said that "no matter what some agency may say, w... 阅读全帖 |
|
a*****1
发帖数: 3134 | 35 With the stock drops like rock and earning power reducing in the future, it
is highly leveraged. The market cap is $27B while debt is $31B. The debt
will be downgraded soon and the financing cost will skyrocket. From here on,
it
will be a downward spiral.
As I have said before, this is the story of ELAN-2002 repeating. Selling
asset is the way out.
发信人: able101 (able101), 信区: Stock
标 题: History is a guide, VRX reminds me of ELN
发信站: BBS 未名空间站 (Fri Oct 30 13:16:45 2015, 美东)
Elan was an Irish bio... 阅读全帖 |
|
a*****1
发帖数: 3134 | 36 With the stock drops like rock and earning power reducing in the future, it
is highly leveraged. The market cap is $27B while debt is $31B. The debt
will be downgraded soon and the financing cost will skyrocket. From here on,
it
will be a downward spiral.
As I have said before, this is the story of ELAN-2002 repeating. Selling
asset is the way out.
发信人: able101 (able101), 信区: Stock
标 题: History is a guide, VRX reminds me of ELN
发信站: BBS 未名空间站 (Fri Oct 30 13:16:45 2015, 美东)
Elan was an Irish bio... 阅读全帖 |
|
g******e
发帖数: 403 | 37 tried many times, always have connection problems when I uploaded my photo.
Is there anyone who has the same problem? |
|
on
发帖数: 199 | 38 It's a medical question, but thought many may know it here.
My hand hurts a lot these days, and I remember some hand problems are caused
by using the keyboard too much. What is the term for that? So I'd like to
check up on internet to see if that is my problem, or not. thanks |
|
w*******r
发帖数: 118 | 39 The process just started.
Finally the ads version is finalized, but in the qualification, it states
that:
A Master’s degree in Computer Science or Management Information Systems and
one to three years’ experience in database administration or the
equivalent combination of education and related experience is required.
the problem is that I only have a Master degree in Engineering and I have 3
years' experience in database amdin. Will this cause problem to my
application?
thanks. |
|
c**i
发帖数: 6973 | 40 【 以下文字转载自 ChinaNews 讨论区 】
发信人: choi (choi), 信区: ChinaNews
标 题: 没有信仰的中国人; No Problem
发信站: BBS 未名空间站 (Sun Mar 2 13:10:28 2008)
"csomefans" wrote 没有信仰的中国人可怕之处.
No problem. CCP (Chinese Communist Party) has come to rescue.
BBC Chinese edition today reports 孔孟故里拟建中华文化标志城.
A quote:
"建设一座新城，以弘扬中国优秀传统文化。* * * 共约三百平方公里的范围。[About
17 km on each side of a square]
"在毛泽东发动的无产阶级文化大革命期间，孔子思想被当作封建社会的残渣余孽受到
清洗。 但最近几年，中国当局似乎重新发现了孔子思想的凝聚力。 一些党内高层人士
更将其视为给日益受西方思潮影响的中国年轻一代注射的一济解毒药。 一名资深共产
党官员甚至说，希望拟建中的中华文化标志城将成为整个中 |
|
l****z
发帖数: 29846 | 41 The question of whether crime in Elizabeth is driven by gangs or drugs is
more than just semantics.
Mayor J. Christian Bollwage has long insisted his city doesn’t have a gang
problem, saying it’s drug crews that commit violence. He has repeatedly
used that as an excuse to reject help from outside agencies such as the
Union County Prosecutor’s Office in fighting gang-related crime. And he
refuses to discuss the issue further, or explain his point of view.
There’s a real consequence to that dogmat... 阅读全帖 |
|
n****r
发帖数: 1568 | 42 Black America's Real Problem Isn't White Racism
Pat Buchanan's column is released twice a week.
Pat BuchananBy Pat Buchanan | Pat Buchanan – Fri, Jul 19, 2013
In the aftermath of the acquittal of George Zimmerman, Eric Holder, Al
Sharpton and Ben Jealous of the NAACP are calling on the black community to
rise up in national protest.
Yet they know — and Barack Obama, whose silence speaks volumes, knows —
nothing is going to happen.
"Stand-Your-Ground" laws in Florida and other states are not goin... 阅读全帖 |
|
a**y
发帖数: 335 | 43 What a coincidence! I also have a 2004 jetta and also had the same problem!
Yes, it's the oxygen sensor's problem. The sympton is when I stop at a
stop sign, the engine sometimes stops. I could restart the engine at first
few times, but it got worse every time. Later on, the engine would even
stop when I slowed down.
My mechanic shop (not a VW dealer) did a good job. They detected and fixed
it quite swiftly. The car has been running fine over 2 years since then.
If you want, I can give yo... 阅读全帖 |
|
s*******e
发帖数: 4188 | 44 I had a nissan sentra many years back that had the same problem. The engine
would stop sometimes when I slow down or stop. Sometimes it's dangerous when
I was making a turn and suddenly lose power steering. I even learned to
start the car while the car was still running at 10-20 mph. :)
I've taken the car to the dealer's. They tried to adjust the engine idle
speed but that didn't seem to work. I got a guess that there was not enough
fuel injected for combustion. No one mentioned the oxygen senso... 阅读全帖 |
|
Q*K
发帖数: 3464 | 45 hehe, os itself is not a simple engineering problem
microsoft still has not get thsi problem solved
but I agree on this:
msft has the worst product and marketing stratgy |
|
c********i
发帖数: 1489 | 46 前一周，听CNN, NPR,92.9等等新闻，最后退役的四架航天飞机，居然没有一个留在了
Houston Johnson Space Center，让人愤怒感慨，特别是本地电台里的人讽刺说 "too
bad we do not have a 212 number".
http://www.nasa.gov/topics/shuttle_station/features/shuttle_map
Atlantis - Florida, Kennedy Space Center
Endeavour - Los Angeles, California Science Center
Discovery - Virgina, Smithsonian
Enterprise - NYC, Air & Space Museum.
大概这又是一个基于政治倾向而非公平性的决定。
凭什么和航空半文钱关系都没有的NYC都可以拿到一个，
而作为关键控制中心的Houston却因为现任总统的愚蠢倾向和党派之争落选？
"Houston, we have a problem"，
不记得有哪个宇航员曾经说过 “New Yo... 阅读全帖 |
|
p****c
发帖数: 8062 | 47 ZT
Larry Brown has a problem, which means the NBA does, too.
With less than two weeks left before the league's reputation goes up for
grabs, too little of what the coach tells his dozen millionaires is getting
through.
Brown wants Team USA to protect the basketball, use the clock, defend every
possession and be prepared to cover each other's backs every time a breakdown
occurs. And that's when he's not scolding somebody for showing up late. In
short, he wants them to play exactly the way his Det |
|
c******s
发帖数: 1994 | 48 EARLY this morning—for viewers in China—the New York Knicks of the new
Taiwanese-American hero Jeremy Lin played against the Dallas Mavericks and
with them China’s current standard-bearer in the NBA: the 7-foot-tall Yi
Jianlian, a high draft pick who has proven a disappointment in America. Mr
Yi's Mavericks lost the game, 104-97, but the bigger loser was Chinese soft
power.
Mr Lin has quickly amassed a huge following among Chinese basketball fans (
and this country does love basketball). This po... 阅读全帖 |
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m**o
发帖数: 9805 | 49 你这是吃果果的鄙视唠嗑的数学水平
no kb = no problem <=> kb = problem |
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b******t
发帖数: 595 | 50 If No Kobe then No problem 的逆否命题是
If there is problem then there is Kobe. |
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