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  • Generate combinations by order and fixed length.

    - by roconmachine
    Suppose there is array main[] = [a,b,c,....z]; a[] = [a1,a2,a3,....] , b[] = [b1,b2,b3,....] and so on. So if we generate combination in main.length of ordered then it looks like ..... a1 b1 c1, a1 b1 c2, a1 b1 c3 ...... a1 b2 c1, a1 b3 c1, ..... a2 b1 c1, a3 b1 c1, ..... and total count will be a.length * b.length * c.length ........ = ? So write a code in any language to generate those combination. all the best. alex

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  • switching default keyevents actions after key combinations

    - by liysd
    I need to change default actions of two events. When I press "enter" one action occurs, when I press "shift-enter" another. I need to switch it. I means if I press "enter" than "shift-enter" action occurs. I tried something like this but if doesn't work. f(evt.keyCode == 13) { if(!evt.shiftKey){ evt.preventDefault(); evt.shiftKey = true; var e = jQuery.Event("keydown"); e.which = 13; e.shiftKey = true; $(wym._doc).trigger(e); Is there any way to do it?

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  • how many color combinations in a 24 bit image

    - by numerical25
    I am reading a book and I am not sure if its a mistake or I am misunderstanding the quote. It reads... Nowadays every PC you can buy has hardware that can render images with at least 16.7 million individual colors. Rather than have an array with thousands of color entries, the images instead contain explicit color values for each pixel. A 24-bit display, of course, uses 24 bits, or 3 bytes per pixel, for color information. This gives 1 byte, or 256 distinct values each, for red, green, and blue. This is generally called true color, because 256^3 (16.7 million) He says 1 byte is equal to 256 distinct values. 1 byte = 8 bits. 8^2 bits = 64 distinct colors right ?? It's not adding up right to me. I know it might be something simple to understand, but I don't understand.

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  • Code Golf: All +-*/ Combinations for 3 integers

    - by Flash84x
    Write a program that takes 3 integers separated by spaces and perform every single combination of addition, subtraction, multiplication and division operations possible and display the result with the operation combination used. Example: $./solution 1 2 3 Results in the following output 1+2+3 = 6 1-2-3 = -4 1*2*3 = 6 1/2/3 = 0 (integer answers only, round up at .5) 1*2-3 = -1 3*1+2 = 5 etc... Order of operation rules apply, assume there will be no parenthesis used i.e. (3-1)*2 = 4 is not a combination, although you could implement this for "extra credit" For results where a divide by 0 occurs simply return NaN

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  • Nested foreach loops for associative array combinations

    - by JohnL
    I have an associative array as follows: $myarray = array('a'=>array(), 'b'=>array(), 'c'=>array(), 'd'=>array()); I want to be able to get all pairs of elements in the array. If it wasn't an associative array, I would use nested for loops, like: for($i=0; $i<count($myarray); $i++) { for($j=$i+1; $j<count($myarray); $j++) { do_something($myarray[$i], $myarray[$j]); } } I have looked at using foreach loops, but as the inner loop goes through ALL elements, some pairs are repeated. Is there a way to do this? Thanks!

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  • Is ctrl-s save universal for save or are there different combinations for different languages

    - by aepheus
    I imagine that there are different combination, just looking for an affirmation. Or, are we developers really that english-centric? If I were in japan, using a word processor on some computer, would ctrl-s save? Are there keyboards where ctrl-s doesn't even exist (non-english keyboards)? Most of what I've seen usually has latin + [insert language here] characters, usually overridden on the normal qwerty keyboard.

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  • assign characters to key combinations in XP or Visual Studio .Net

    - by cpj
    I'm running Mac OSX on a MacBookPro (UK keyboard). I run windows XP under parallels in a VM. I run Visual Studio .Net 2003 and 2008 in XP in the VM when i need to. I have English United Kingdom and English United states keyboards setup in XP. (they switch sometimes for no apparent reason) There is no hash "#" key on my mac's keyboard. However, in OSX I can get a hash with an alt+3 key combination. But In Windows XP... I can not make a "#" character. I can go to the character map in windows and copy a hash.. switch into OSX and copy a hash.. search in code and copy a hash.. but I can not make a hash in XP using my keyboard without typing U+0023: ... which you can imagine is annoying. coding anything with hash symbols is becoming a choir. Anyone got any advice or key mapping tricks I can use to get hash characters working in XP using my mac UK keyboard?

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  • python -> combinations of numbers and letters

    - by tekknolagi
    #!/usr/bin/python import random lower_a = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'] upper_a = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'] num = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9'] all = [] all = " ".join("".join(lower_a) + "".join(upper_a) + "".join(num)) all = all.split() x = 1 c = 1 while x < 10: y = [] for i in range(c): a = random.choice(all) y.append(a) print "".join(y) x += 1 c += 1 what i have now outputs something like the following: 5 hE HAy 1kgy Pt6JM 2pFuCb Jv5osaX 5q8PwWAO SvHWRKfI5 how can i make it systematically go through every combination of letters (upper and lowercase) for a given length, then add 1 to that length and repeat the process?

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  • What category of combinatorial problems appear on the logic games section of the LSAT?

    - by Merjit
    There's a category of logic problem on the LSAT that goes like this: Seven consecutive time slots for a broadcast, numbered in chronological order I through 7, will be filled by six song tapes-G, H, L, O, P, S-and exactly one news tape. Each tape is to be assigned to a different time slot, and no tape is longer than any other tape. The broadcast is subject to the following restrictions: L must be played immediately before O. The news tape must be played at some time after L. There must be exactly two time slots between G and P, regardless of whether G comes before P or whether G comes after P. I'm interested in generating a list of permutations that satisfy the conditions as a way of studying for the test and as a programming challenge. However, I'm not sure what class of permutation problem this is. I've generalized the type problem as follows: Given an n-length array A: How many ways can a set of n unique items be arranged within A? Eg. How many ways are there to rearrange ABCDEFG? If the length of the set of unique items is less than the length of A, how many ways can the set be arranged within A if items in the set may occur more than once? Eg. ABCDEF = AABCDEF; ABBCDEF, etc. How many ways can a set of unique items be arranged within A if the items of the set are subject to "blocking conditions"? My thought is to encode the restrictions and then use something like Python's itertools to generate the permutations. Thoughts and suggestions are welcome.

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  • Generating Mouse-Keyboard combination events in python

    - by freakazo
    I want to be able to do a combination of keypresses and mouseclicks simultaneously, as in for example Control+LeftClick At the moment I am able to do Control and then a left click with the following code: import win32com, win32api, win32con def CopyBox( x, y): time.sleep(.2) wsh = win32com.client.Dispatch("WScript.Shell") wsh.SendKeys("^") win32api.SetCursorPos((x,y)) win32api.mouse_event(win32con.MOUSEEVENTF_LEFTDOWN, x, y, 0, 0) win32api.mouse_event(win32con.MOUSEEVENTF_LEFTUP, x, y, 0, 0) What this does is press control on the keyboard, then it clicks. I need it to keep the controll pressed longer and return while it's still pressed to continue running the code. Is there a maybe lower level way of saying press the key and then later in the code tell it to lift up the key such as like what the mouse is doing?

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  • grouping objects to achieve a similar mean property for all groups

    - by cytochrome
    I have a collection of objects, each of which has a numerical 'weight'. I would like to create groups of these objects such that each group has approximately the same arithmetic mean of object weights. The groups won't necessarily have the same number of members, but the size of groups will be within one of each other. In terms of numbers, there will be between 50 and 100 objects and the maximum group size will be about 5. Is this a well-known type of problem? It seems a bit like a knapsack or partition problem. Are efficient algorithms known to solve it? As a first step, I created a python script that achieves very crude equivalence of mean weights by sorting the objects by weight, subgrouping these objects, and then distributing a member of each subgroup to one of the final groups. I am comfortable programming in python, so if existing packages or modules exist to achieve part of this functionality, I'd appreciate hearing about them. Thank you for your help and suggestions.

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  • Count in base 2, 3, 4 etc in Java and output all permutations

    - by tree-hacker
    I want to write a function in Java that takes as input an integer and outputs every possible permutation of numbers up to that integer. For example: f(1) 0 f(2) should output: 00 01 10 11 f(3) should output: 000 001 002 010 011 012 020 021 022 100 .... 220 221 222 That is it should output all 27 permutations of the digits of the numbers 0, 1, 2. f(4) should output 0000 0001 0002 0003 0010 ... 3330 3331 3332 3333 f(4) should output 00000 00001 ... 44443 44444 I have been trying to solve this problem but cannot seem to work out how to do it and keep getting confused by how many loops I need. Does anyone know how to solve this problem? Thanks in advance.

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  • yet another logic.

    - by Sunil
    I'm working on a research problem out of curiosity and I don't know how to program the logic that I've in mind. Let me explain it to you : I've 4 vectors say for example, v1 = 1 1 1 1 v2 = 2 2 2 2 v3 = 3 3 3 3 v4 = 4 4 4 4 Now what I want to do is to add them combination-wise. i.e v12 = v1+v2 v13 = v1+v3 v14 = v1+v4 v23 = v2+v3 v24 = v2+v4 v34 = v3+v4 Till this step it is just fine. The problem/trick is now, at the end of each iteration I give the obtained vectors into a black box function and it returns only few of the vectors say v12, v13 and v34. Now, I want to add each of these vectors one vector from v1,v2,v3,v4 which it hasn't added before. For example v3 and v4 hasn't been added to v12 so I want to create v123 and v124. similarly for all the vectors like, v12 should become : v123 = v12+v3 v124 = v12+v4 v13 should become : v132 // this should not occur because I already have v123 v134 = v13+v4; v14,v23 and v24 cannot be considered because it was deleted in the black box function so all we have in our hands to work with is v12,v13 and v34. v34 should become : v341 // cannot occur because we have 134 v342 = v34+v2 It is important that I do not do all at one step at the start like for example I can do (4 choose 3) 4C3 and finish it off but I want to do it step by step at each iteration. I've asked a modified version of this question before (without including the black box function) and got answers here. Can anybody tell me how to do it when the black box function is included ? A modification of the previous answer would also be great. Thanks in advance.

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  • Investigation: Can different combinations of components effect Dataflow performance?

    - by jamiet
    Introduction The Dataflow task is one of the core components (if not the core component) of SQL Server Integration Services (SSIS) and often the most misunderstood. This is not surprising, its an incredibly complicated beast and we’re abstracted away from that complexity via some boxes that go yellow red or green and that have some lines drawn between them. Example dataflow In this blog post I intend to look under that facade and get into some of the nuts and bolts of the Dataflow Task by investigating how the decisions we make when building our packages can affect performance. I will do this by comparing the performance of three dataflows that all have the same input, all produce the same output, but which all operate slightly differently by way of having different transformation components. I also want to use this blog post to challenge a common held opinion that I see perpetuated over and over again on the SSIS forum. That is, that people assume adding components to a dataflow will be detrimental to overall performance. Its not surprising that people think this –it is intuitive to think that more components means more work- however this is not a view that I share. I have always been of the opinion that there are many factors affecting dataflow duration and the number of components is actually one of the less important ones; having said that I have never proven that assertion and that is one reason for this investigation. I have actually seen evidence that some people think dataflow duration is simply a function of number of rows and number of components. I’ll happily call that one out as a myth even without any investigation!  The Setup I have a 2GB datafile which is a list of 4731904 (~4.7million) customer records with various attributes against them and it contains 2 columns that I am going to use for categorisation: [YearlyIncome] [BirthDate] The data file is a SSIS raw format file which I chose to use because it is the quickest way of getting data into a dataflow and given that I am testing the transformations, not the source or destination adapters, I want to minimise external influences as much as possible. In the test I will split the customers according to month of birth (12 of those) and whether or not their yearly income is above or below 50000 (2 of those); in other words I will be splitting them into 24 discrete categories and in order to do it I shall be using different combinations of SSIS’ Conditional Split and Derived Column transformation components. The 24 datapaths that occur will each input to a rowcount component, again because this is the least resource intensive means of terminating a datapath. The test is being carried out on a Dell XPS Studio laptop with a quad core (8 logical Procs) Intel Core i7 at 1.73GHz and Samsung SSD hard drive. Its running SQL Server 2008 R2 on Windows 7. The Variables Here are the three combinations of components that I am going to test:     One Conditional Split - A single Conditional Split component CSPL Split by Month of Birth and income category that will use expressions on [YearlyIncome] & [BirthDate] to send each row to one of 24 outputs. This next screenshot displays the expression logic in use: Derived Column & Conditional Split - A Derived Column component DER Income Category that adds a new column [IncomeCategory] which will contain one of two possible text values {“LessThan50000”,”GreaterThan50000”} and uses [YearlyIncome] to determine which value each row should get. A Conditional Split component CSPL Split by Month of Birth and Income Category then uses that new column in conjunction with [BirthDate] to determine which of the same 24 outputs to send each row to. Put more simply, I am separating the Conditional Split of #1 into a Derived Column and a Conditional Split. The next screenshots display the expression logic in use: DER Income Category         CSPL Split by Month of Birth and Income Category       Three Conditional Splits - A Conditional Split component that produces two outputs based on [YearlyIncome], one for each Income Category. Each of those outputs will go to a further Conditional Split that splits the input into 12 outputs, one for each month of birth (identical logic in each). In this case then I am separating the single Conditional Split of #1 into three Conditional Split components. The next screenshots display the expression logic in use: CSPL Split by Income Category         CSPL Split by Month of Birth 1& 2       Each of these combinations will provide an input to one of the 24 rowcount components, just the same as before. For illustration here is a screenshot of the dataflow containing three Conditional Split components: As you can these dataflows have a fair bit of work to do and remember that they’re doing that work for 4.7million rows. I will execute each dataflow 10 times and use the average for comparison. I foresee three possible outcomes: The dataflow containing just one Conditional Split (i.e. #1) will be quicker There is no significant difference between any of them One of the two dataflows containing multiple transformation components will be quicker Regardless of which of those outcomes come to pass we will have learnt something and that makes this an interesting test to carry out. Note that I will be executing the dataflows using dtexec.exe rather than hitting F5 within BIDS. The Results and Analysis The table below shows all of the executions, 10 for each dataflow. It also shows the average for each along with a standard deviation. All durations are in seconds. I’m pasting a screenshot because I frankly can’t be bothered with the faffing about needed to make a presentable HTML table. It is plain to see from the average that the dataflow containing three conditional splits is significantly faster, the other two taking 43% and 52% longer respectively. This seems strange though, right? Why does the dataflow containing the most components outperform the other two by such a big margin? The answer is actually quite logical when you put some thought into it and I’ll explain that below. Before progressing, a side note. The standard deviation for the “Three Conditional Splits” dataflow is orders of magnitude smaller – indicating that performance for this dataflow can be predicted with much greater confidence too. The Explanation I refer you to the screenshot above that shows how CSPL Split by Month of Birth and salary category in the first dataflow is setup. Observe that there is a case for each combination of Month Of Date and Income Category – 24 in total. These expressions get evaluated in the order that they appear and hence if we assume that Month of Date and Income Category are uniformly distributed in the dataset we can deduce that the expected number of expression evaluations for each row is 12.5 i.e. 1 (the minimum) + 24 (the maximum) divided by 2 = 12.5. Now take a look at the screenshots for the second dataflow. We are doing one expression evaluation in DER Income Category and we have the same 24 cases in CSPL Split by Month of Birth and Income Category as we had before, only the expression differs slightly. In this case then we have 1 + 12.5 = 13.5 expected evaluations for each row – that would account for the slightly longer average execution time for this dataflow. Now onto the third dataflow, the quick one. CSPL Split by Income Category does a maximum of 2 expression evaluations thus the expected number of evaluations per row is 1.5. CSPL Split by Month of Birth 1 & CSPL Split by Month of Birth 2 both have less work to do than the previous Conditional Split components because they only have 12 cases to test for thus the expected number of expression evaluations is 6.5 There are two of them so total expected number of expression evaluations for this dataflow is 6.5 + 6.5 + 1.5 = 14.5. 14.5 is still more than 12.5 & 13.5 though so why is the third dataflow so much quicker? Simple, the conditional expressions in the first two dataflows have two boolean predicates to evaluate – one for Income Category and one for Month of Birth; the expressions in the Conditional Split in the third dataflow however only have one predicate thus they are doing a lot less work. To sum up, the difference in execution times can be attributed to the difference between: MONTH(BirthDate) == 1 && YearlyIncome <= 50000 and MONTH(BirthDate) == 1 In the first two dataflows YearlyIncome <= 50000 gets evaluated an average of 12.5 times for every row whereas in the third dataflow it is evaluated once and once only. Multiply those 11.5 extra operations by 4.7million rows and you get a significant amount of extra CPU cycles – that’s where our duration difference comes from. The Wrap-up The obvious point here is that adding new components to a dataflow isn’t necessarily going to make it go any slower, moreover you may be able to achieve significant improvements by splitting logic over multiple components rather than one. Performance tuning is all about reducing the amount of work that needs to be done and that doesn’t necessarily mean use less components, indeed sometimes you may be able to reduce workload in ways that aren’t immediately obvious as I think I have proven here. Of course there are many variables in play here and your mileage will most definitely vary. I encourage you to download the package and see if you get similar results – let me know in the comments. The package contains all three dataflows plus a fourth dataflow that will create the 2GB raw file for you (you will also need the [AdventureWorksDW2008] sample database from which to source the data); simply disable all dataflows except the one you want to test before executing the package and remember, execute using dtexec, not within BIDS. If you want to explore dataflow performance tuning in more detail then here are some links you might want to check out: Inequality joins, Asynchronous transformations and Lookups Destination Adapter Comparison Don’t turn the dataflow into a cursor SSIS Dataflow – Designing for performance (webinar) Any comments? Let me know! @Jamiet

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  • Alchemy like game for the web, open source. Any ideas for element combinations?

    - by JohnDel
    I created a web game like the Android game Alchemy. It's open source and in the back-end you can create your own elements / your own game. I was wondering what elements - ideas would be good to implement as a prototype / demo? Some ideas are: Colors Programming languages Chemical Compounds Same as the original alchemy Evolution of biological organisms What do you think? Any specific combination ideas?

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  • MySQL Query to receive random combinations from two tables.

    - by Michael
    Alright, here is my issue, I have two tables, one named firstnames and the other named lastnames. What I am trying to do here is to find 100 of the possible combinations from these names for test data. The firstnames table has 5494 entries in a single column, and the lastnames table has 88799 entries in a single column. The only query that I have been able to come up with that has some results is: select * from (select * from firstnames order by rand()) f LEFT JOIN (select * from lastnames order by rand()) l on 1=1 limit 10; The problem with this code is that it selects 1 firstname and gives every lastname that could go with it. While this is plausible, I will have to set the limit to 500000000 in order to get all the combinations possible without having only 20 first names(and I'd rather not kill my server). However, I only need 100 random generations of entries for test data, and I will not be able to get that with this code. Can anyone please give me any advice?

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  • Trying to use table aliases in SQL...

    - by user366685
    I'm a graphic designer trying my best to understand table aliases, but it's not working. Here's what I have so far: SELECT colours.colourid AS colourid1, combinations.manufacturercolourid AS colourmanid1, colours.colourname AS colourname1, colours.colourhex AS colourhex1, combinations.qecolourid2 AS colouridqe2, colours.colourid AS colourid2, colours.colourname AS colourname2, colours.colourhex AS colourhex2, colours.colourid AS colourid3, combinations.qecolourid3 AS colouridqe3, colours.colourname AS colourname3, colours.colourhex AS colourhex3, colours.colourid AS colourid4, combinations.qecolourid4 AS colouridqe4, colours.colourname AS colourname4, colours.colourhex AS colourhex4, combinations.coloursupplierid FROM combinations INNER JOIN colours ON colours.colourid = combinations.manufacturercolourid; Now, the idea is that in the colours lookup table, the id will pull the colour code, hex and name from the lookup table so that I can pull the colour code, hex and name for the 4 colours that I'm looking for. I can get this to work, but it only pulls up the first name, code and hex and I'm just not seeing what I'm doing wrong.

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  • How to send Ctrl/Shift/Alt + Key combinations to an application window? (via SendMessage)

    - by user1792042
    I can successfully send any single key message to an application, but don't know how to send combinations of keys (like Ctrl+F12, Shift+F1, Ctrl+R, etc..) Tired doing this that way: SendMessage(handle, WM_KEYDOWN, Keys.Control, 0); SendMessage(handle, WM_KEYDOWN, Keys.F12, 0); SendMessage(handle, WM_KEYUP, Keys.F12, 0); SendMessage(handle, WM_KEYUP, Keys.Control, 0); but this doen not seems to work.. (application act like only F12 is pressed, not Ctrl+F12).. Any ideas how to make this work?

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  • How can I generate a list of words made up of combinations of three word lists in Perl?

    - by Chris Denman
    I have three lists of words. I would like to generate a single list of all the combinations of words from the three lists. List 1: red green blue List 2: one two List 3: apple banana The final list would like like so: red one apple red two apple red one banana red two banana ... and so on Ideally I'd like to pass in three arrays and the routine return one array. I have done a simple loop like so: foreach $word1 (@list1){ foreach $word2 (@list2){ foreach $word3 (@list3){ print "$word1 $word2 $word3\n"; } } } However, this doesn't work if there's nothing in the second or third list (I may only want to iterate between one, two or three lists at a time - in other words, if I only supply two lists it should iterate between those two lists).

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