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David,
It would be interesting to see how they converted it, however, I have already done that and it works great and I don't need to spend the money to see what they did. The primary fix was to get rid of all of the int's and make them CBT defined types, each one different so you knew what you were dealing with, then define these types as either Signed/Unsigned Longs or Signed/Unsigned Shorts depending on whether you wanted a version to be able to read an old database.
If you do get the source, I can give you my fixes for a PurgeTree to quickly kill a tree that is no longer needed.
Dave.
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My office is testing a bunch of folks who have applied for Java jobs. I don't know head and tails
of the language other than that its syntax is stolen from here and there (I'm still partyin' with
MFC/Win32, yay!). My buddy was the invigilator and got the questions' sheet. This was one of the
easiest assignments, and shockingly, only 3 out of the 14 people that attempted this problem finished
it correctly on time. Some took more than 45 minutes but got it right, and others didn't solve it at
all! I tried it for the hell of it beat the time by 29 minutes, finishing at 16 minutes (C/DevCPP),
which I guess is not bad. Post your times here, and see if you can bring it down below 16 minutes. 
Q7. (Note: You cannot answer Questions 8, 11 and 14 if you are answering this question.
Pick another 2 from the rest).
Write a command-line program as follows:
First the program will take as input a +ve integer from the user, let's call it
the TARGET.
It will then take in a set of +ve integers from the user, and here the user gets
to specify how many integers he/she wants to enter. Let's call this set the
RANGE.
Now the program should compute as follows:
- Find all combinations in the RANGE, the sum of which add up to the
target. Print such combinations at the command prompt. In a combination,
repeats are not allowed. i.e. (x + x + y) = TARGET is forbidden. Every element
in the combination must be unique.
- In case a user enters a RANGE element greater than the target, it should be immediately
discarded and the user must be prompted for the element again.
- Order shifted cases don't count. i.e. (x+y) and (y+x) being printed
separately is unnecessary and MUST be avoided.
- In case no combinations exist, the program should report so.
- Add exception handling code where necessary.
Example Run:
Enter Target: 15
How many set elements?: 5
Enter Element1: 7
Enter Element2: 8
Enter Element3: 12
Enter Element4: 3
Enter Element5: 22
Sorry. That element is larger than your target. Try again.
Enter Element5: 4
Combinations are:
1] 7+8
2] 8+3+4
3] 12+3
Time: 45 mins.
(At the top of the source file, please comment in your ID details along with the reference
number at the back of the day-card you were provided by the examiner. Write your Full Name,
ID key, TDC number and most importantly the reference number. Good luck.)
ASP - AJAX is SEXY. PERIOD.
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#include <iostream>
#include <vector>
#include <algorithm>
#include <numeric>
template <class BidirectionalIterator>
bool next_combination(BidirectionalIterator first,
BidirectionalIterator k,
BidirectionalIterator last);
int main()
{
std::vector<int> v;
v.push_back(7);
v.push_back(8);
v.push_back(12);
v.push_back(3);
v.push_back(4);
int target = 15;
int combination_count = 0;
std::sort(v.begin(),v.end());
for(unsigned int i = 1; i <= v.size(); ++i)
{
std::vector<int> tmp;
std::copy(v.begin(),v.end(),std::back_inserter(tmp));
do
{
if (std::accumulate(tmp.begin(),tmp.begin() + i, 0) == target)
{
std::cout << ++combination_count << "] ";
for(unsigned int j = 0; j < i; ++j)
{
std::cout << tmp[j] << (j < (i-1) ? "+" : "\n");
}
}
}
while(next_combination(tmp.begin(),tmp.begin() + i,tmp.end()));
}
if (0 == combination_count)
{
std::cout << "No combinations found." < std::endl;
}
return 0;
}
template <class BidirectionalIterator>
bool next_combination(BidirectionalIterator first,
BidirectionalIterator k,
BidirectionalIterator last)
{
if ((first == last) || (k == first) || (k == last)) return false;
BidirectionalIterator i = first;
BidirectionalIterator ii = last;
++i;
if (i == last) return false;
i = last;
--i;
i = k;
--ii;
while (i != first)
{
if (*--i < *ii)
{
BidirectionalIterator j = k;
while(!(*i < *j)) j++;
iter_swap(i,j);
i++;j++;ii=k;
rotate(i,j,last);
while(j!=last){ ++j; ++ii;}
rotate(k,ii,last);
return true;
}
}
rotate (first,k,last);
return false;
}
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class SubsetSummer<br />
{<br />
static IEnumerable< long> SubsetSumCore(IList< int> values, int target)<br />
{<br />
long mask = (1 << values.Count);<br />
<br />
while(mask-- > 0)<br />
{<br />
int total = 0;<br />
for(int bit = 0; bit< values.Count; bit++)<br />
{<br />
if ((mask & 1 << bit) > 0) total += values[bit];<br />
}<br />
<br />
if (total == target) yield return mask;<br />
}<br />
}<br />
<br />
static IEnumerable< List< int>> SubsetSum(IList< int> values, int target)<br />
{<br />
foreach (var resultMask in SubsetSumCore(values,target))<br />
{<br />
var results = new List< int>();<br />
for (int bit = 0; bit < values.Count; bit++)<br />
{<br />
if ((resultMask & 1 << bit) > 0) results.Add(values[bit]);<br />
}<br />
yield return results;<br />
}<br />
}<br />
<br />
static void Main(string[] args)<br />
{<br />
var values = new []{7, 8, 12, 3, 4};<br />
<br />
foreach (var result in SubsetSum(values, 15))<br />
{<br />
Console.WriteLine(string.Join(" + ", result.ConvertAll(i => i.ToString()).ToArray()));<br />
}<br />
}<br />
}
(wow that really shagged my generics)
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Sorry you have failed. The program does not meet the requirements. Where is the user input and validation?
If it does not need to meet them then this program will do the job and take a lot less time and thought.
class SubsetSummer
{
static void Main(string[] args)
{
Console.WriteLine("3 + 4 + 8");
Console.WriteLine("3 + 12");
Console.WriteLine("7 + 8");
}
}
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You forgot to place this in the punintended namespace.
ASP - AJAX is SEXY. PERIOD.
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I guess if you find user input and validation challenging then you can focus on those parts. This is maths & algs, not "C# 101".
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Hi all,
I read about several methods for constructing an ellipse with straightedge and compass, and one seemed very peculiar to me. It was called the trammel method...and it's the only one that I can't prove. It seemed so simple, but I just can't prove it. 
If anyone could find a proof for me or point me in the right direction?
And also if this is in the wrong section please kindly inform me which section it should be in.
Thanks.
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What do you mean by 'proof'? Are you implying you want an algebraic proof of the trammel method?
There is a web page here[^] that explains how to do it using a trammel and a nice animated one here[^].
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Hi,
the proof is rather simple:
let the coordinates of A,B and O be called (x,y), (xB,0) and (0,yO) respectively. Then (based on AB=b and BO=AO-AB=a-b):
xB= x*(a-b)/a
yO= -y*(a-b)/b
(congruent triangles, or rule of three)
Now triangle "B,O,origin" is rectangular, hence xB*xB + yO*yO = (a-b)*(a-b)
(Pythagoras)
substituting the earlier formulae for xB and yO, and simplifying yields
(x/a)^2 + (y/b)^2 = 1
which is exactly the equation of an ellipse with radii a and b. QED.
modified on Sunday, October 26, 2008 3:08 PM
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Now I just feel stupid. 
Thanks.
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hi Dear,
I have one item and its Avg Selling Price is 10 and Qty is 10 which makes its value to 10 * 10 =100
so now if i do some purchase and get one more item on the Price of 4 then it makes Qty 10+1 =11
and Avg Selling Price 100 + 4 =104
while if if divide 104 / 11 = 9.45 so its Avg Price becomes 9.45 and if i multiply
9.45 *11 =103.95
while my stock value is 104 means loss of 0.05
any Suggestion
Thanks in Adv
regards,
Mirza Rahman
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softdev_sup wrote: any Suggestion
Yes, use a better calculator or rational numbers.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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Dividing 104 by 11 is 9.4545454545454545....
Because you are truncating after two decimal places you lose numerical precision. If you do the calculation keeping everything explicitly in fraction notation, you will see it comes out to 104.
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Thanks for replying but i have to store this value in database which is user defined and max up to 8 , any other solution
because when we round up to 8 same problem comes
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I'd suggest storing the intermediate values and compute the value when you need it.
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I suggest the same solution as Andrew.
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Go with Andrew's suggestion. It is better to just do the calculations when you actually need to use them, rather than trying to store in the database and having the issue you are running into.
"The clue train passed his station without stopping." - John Simmons / outlaw programmer
"Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon
"Not only do you continue to babble nonsense, you can't even correctly remember the nonsense you babbled just minutes ago." - Rob Graham
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I hope you don't mean you're storing these values as varchar/text/string etc.
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When performing calculations on real numbers it's usually best to utilize the full precision of the machine or database environment, then do any rounding only at the final step. If that means you have to carry internal data to 6 decimals, so be it. It doesn't cost you anything in performance and will save a lot of grief when users start looking at your results.
"A Journey of a Thousand Rest Stops Begins with a Single Movement"
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Hi,
in order to preserve accuracy, you should keep track of the total amount
(104 in your example) and the total quantity (11). The Avg Selling Price
is of secondary importance. You should not perform a division (which
looses accuracy, especially if you apply rounding to the quotient) and
later try to undo it by multiplying again, just keep track of amount and count.
Amount has no precision problem, since it has a fixed resolution (e.g. 1 cent),
and count is an integer.
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Excellent read[^]. It might solve a problem of mine if I can implement it a certain way.
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I have a large number of articles. I have a large number of possible keywords. Each article has at least one keyword associated with it, but may have many keywords. There is a database containing a list of all articles and a boolean variable set to true for each keyword if that keyword applies.
A user has a list of all keywords and selects those which interest them.
I am trying to find a more elegant way to extract the list of relevant articles than a brute force SQL SELECT.
Any suggestions would be appreciated!
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I guess you will not be able to escape from a select statement...maybe you could try to use a stored procedure for that, or try to optimize the select, but not without a select I think
Intelligence is almost useless for those who have nothing else!
Email: caiokf@gmail.com
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I think your database design is not ideal.. You should have a table for all the articles and a table for all possible keywords. In a third table you save all keyword-article associations (using the primary key of the article and keyword).
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