sequences

Newbie question and yes I have spent a lot of time sifting through similar questions and Answers with no luck. What I am trying to do is save frames from a video file in a sequential order. I have managed to save one image using c and I cannot seem to save images after that. I have started using c++ in opencv instead of c and all I can do is view the video and not save any jpg's from it. I am using opencv2.4.4a on mac if that helps. below is my c example #include <stdio.h> #include <stdlib.h> #include <opencv/cv.h> #include <opencv/highgui.h> #include <iostream> using namespace cv; using

I want to create a sequence for this varchar. It would have been easier had it been a number instead of varchar. In that case, I could do seq_no := seq_no + 1; But what can I do when I want to store next value in column as A0000002, when the previous value was A0000001 (to increment the number in the next varchar rowby 1)? GKV This can be done by to_char(seq_no,'FM0000000') your example can be done by creating sequence in oracle create sequence seq_no start with 1 increment by 1; then select 'A'||to_char(seq_no.nextval,'FM0000000') from dual; Right now i have used in dual ..but place this 'A'|

We have an increasing sequence in which each element is consist of even digits only (0, 2, 4, 6, 8). How can we find the nth number in this sequence Is it possible to find nth number in this sequence in O(1) time. Sequence: 0, 2, 4, 6, 8, 20, 22, 24, 26, 28, 40, 42, 44, 46, 48, 60, 62, 64, 66, 68, 80, 82, 84, 86, 88, 200, 202 and so on. The nth number in this sequence is n in base 5, with the digits doubled. def base5(n): if n == 0: return for x in base5(n // 5): yield x yield n % 5 def seq(n): return int(''.join(str(2 * x) for x in base5(n)) or '0') for i in xrange(100): print i, seq(i) This

Can you suggest simpler and clearer way to write this function? let cartesian_product sequences = let step acc sequence = seq { for x in acc do for y in sequence do yield Seq.append x [y] } Seq.fold step (Seq.singleton Seq.empty) sequences Less elegant, but (seems to be) faster solution: let cartesian_product2 sequences = let step acc sequence = seq { for x in acc do for y in sequence do yield seq { yield! x ; yield y } } Seq.fold step (Seq.singleton Seq.empty) sequences ; > cartesian items |> Seq.length;; Real: 00:00:00.405, CPU: 00:00:00.405, GC gen0: 37, gen1: 1, gen2: 0 val it : int =

Background: I have a sequence of contiguous, time-stamped data. The data-sequence has gaps in it where the data is not contiguous. I want create a method to split the sequence up into a sequence of sequences so that each subsequence contains contiguous data (split the input-sequence at the gaps). Constraints: The return value must be a sequence of sequences to ensure that elements are only produced as needed (cannot use list/array/cacheing) The solution must NOT be O(n^2), probably ruling out a Seq.take - Seq.skip pattern (cf. Brian's post) Bonus points for a functionally idiomatic approach

Given a BST, find all sequences of nodes starting from root that will essentially give the same binary search tree. Given a bst, say 3 / \ 1 5 the answer should be 3,1,5 and 3,5,1. another example 5 / \ 4 7 / / \ 1 6 10 the outputs will be 5,4,1,7,6,10 5,4,7,6,10,1 5,7,6,10,4,1 etc The invariant here however is that the parent's index must always be lesser than its children. I am having difficulty implementing it. Atul Vaibhav I assume you want a list of all sequences which will generate the same BST. In this answer, we will use Divide and Conquer . We will create a function findAllSequences

I'm converting a db from postgres to mysql. Since i cannot find a tool that does the trick itself, i'm going to convert all postgres sequences to autoincrement ids in mysql with autoincrement value. So, how can i list all sequences in a Postgres DB ( 8.1 version) with information about the table in which it's used, the next value etc with a SQL query? Be aware that i can't use the information_schema.sequences view in the 8.4 release. Anand Chitipothu The following query gives names of all sequences. SELECT c.relname FROM pg_class c WHERE c.relkind = 'S'; Typically a sequence is named as $