powerset

I have two lists of vertices: V and S . I would like to generate all possible directed graphs from V and S so, that each vertex from V has only one out-edge and exactly one in-edge, and each vertex from S can have any number of in- and out- edges. Each graph in the result should contain exactly all vertices from V and from S . The result can contain both connected and disconnected graphs. First I thought it was a powerset-related problem, but powerset has many other sets that may contain just one element (and I do not need those). My current strategy is to: find all pairs between vertices from

I want to select columns from a data frame so that the resulting continuous column-sequences are as long as possible, while the number of rows with NAs is as small as possible, because they have to be dropped afterwards. (The reason I want to do this is, that I want to run TraMineR::seqsubm() to automatically get a matrix of transition costs (by transition probability) and later run cluster::agnes() on it. TraMineR::seqsubm() doesn't like NA states and cluster::agnes() with NA states in the matrix doesn't necessarily make much sense.) For that purpose I already wrote a working function that

This question already has an answer here: How to get all subsets of a set? (powerset) 17 answers I am trying to implement a function to generate the powerset of a list xs . The general idea is that we walk through the elements of xs and choose whether to include x or not. The problem I'm facing is that withX ends up being equal to [None] (a singleton list with None ) because (I think) s.add(x) returns None . This isn't a homework assignment, it's an exercise in Cracking the Coding Interview. def powerSetBF(xs): powerSet = [] powerSet.append(set([])) for x in xs: powerSetCopy = powerSet[:]

i am using the following C# function to get a powerset limited to subsets of a minimal length string[] PowerSet(int min_len, string set) { IEnumerable<IEnumerable<string>> seed = new List<IEnumerable<string>>() { Enumerable.Empty<string>() }; return set.Replace(" ", "") .Split(',') .Aggregate(seed, (a, b) => a.Concat(a.Select(x => x.Concat(new[] { b })))) .Where(subset => subset.Count() >= min_len) .Select(subset => string.Join(",", subset)) .ToArray(); } the problem is that when the original set is large, the algorithm has to work very hard even if the minimal length is large as well. e.g:

I need a t-sql code to get powerset of a resultset. example input : ColumnName 1 2 3 Example Output(one columns as nvarchar) : 1 2 3 1,2 1,3 2,3 1,2,3 Output set may contain duplicate values such as (1,3 vs 3,1). You can use this one and get full powerset. Enjoy it. --EXEC PowerSet 'A,B,C,D' Create PROCEDURE PowerSet(@Members NVARCHAR(64)) As Begin Declare @SubSet NVARCHAR(Max), @SubSetCount int, @Counter1 int, @Counter2 int, @ID int Create table #Members ( ID int IDENTITY(1,1) PRIMARY KEY, Member NVARCHAR(50) ) Create table #PowerSets ( SubSet NVARCHAR(50) ) -- Start Convert @Members To Table

With n=5 and k=3 the following loop will do it List<String> l=new ArrayList<String>(); l.add("A");l.add("B");l.add("C");l.add("D");l.add("E"); int broadcastSize = (int) Math.pow(2, l.size()); for (int i = 1; i < broadcastSize; i++) { StringBuffer buffer = new StringBuffer(50); int mask = i; int j = 0; int size=0; System.out.println(); while (mask > 0) { if ((mask & 1) == 1) { System.out.println(".. "+mask); buffer.append(l.get(j)); if (++size>3){ buffer = new StringBuffer(50); break; } } System.out.println(" "+mask); mask >>= 1; j++; } if (buffer.length()>0) System.out.println(buffer.toString(

I tried to create the code to generate all possible combination of the given string in the lexicographical order: The code that I wrote is: void get(char *n) { int l=strlen(n); sort(n,n+l); int k=0,m,i,j,z; while(k<l) { m=k; for(i=k;i<l;i++) { for(j=k;j<=i;j++) cout<<n[j]; cout<<"\n"; } for(z=m+2;z<l;z++) cout<<n[m]<<n[z]<<"\n"; k++; } } int main() { char n[100]; cin>>n; get(n); return 0; } Suppose the string is : abcde My code is not generating combinations like: abd abe The output I am getting for the string abcde are: a ab abc abcd abcde ac ad ae b bc bcd bcde bd be c cd cde ce d de e My