transitiveClosure - SeqAn API Documentation

# fn() transitiveClosure
Determines whether there is a path between any two given vertices or not.

Defined in | <seqan/graph_algorithms.h>
Signature | `void transitiveClosure(closure, g);`

## Parameters

`closure` | A matrix which indicates the closure. Entry (i,j) in this matrix indicates whether there is a path from i to j in the graph or not. Types: Matrix
`g` | A directed graph. Types: Directed Graph

## Detailed Description

### Example

    #include <iostream>
    #include <seqan/graph_algorithms.h>

    using namespace seqan;

    int main()
    {
        typedef Graph<Directed<> > TGraph;
        typedef VertexDescriptor<TGraph>::Type TVertexDescriptor;
        typedef Size<TGraph>::Type TSize;

        // Create graph with 5 directed edges (3,0), (1,2), ...
        TSize numEdges = 5;
        TVertexDescriptor edges[] = {3, 0, 1, 2, 2, 1, 1, 3, 3, 2};
        TGraph g;
        addEdges(g, edges, numEdges);
        // Print graph to stdout.
        std::cout << g << "\n";

        // Compute transitive closure.
        String<bool> closure;
        transitiveClosure(closure, g);

        // Print result to stdout.
        TSize len = static_cast<TSize>(std::sqrt((double) length(closure)));
        for (TSize row = 0; row < len; ++row)
        {
            for (TSize col = 0; col < len; ++col)
                std::cout << getValue(closure, row * len + col) << ",";
            std::cout << std::endl;
        }

        return 0;
    }

Demo: demos/dox/graph_algorithms/transitive_closure.cpp

    Adjacency list:
    0 ->
    1 -> 3,2,
    2 -> 1,
    3 -> 2,0,
    Edge list:
    Source: 1,Target: 3 (Id: 3)
    Source: 1,Target: 2 (Id: 1)
    Source: 2,Target: 1 (Id: 2)
    Source: 3,Target: 2 (Id: 4)
    Source: 3,Target: 0 (Id: 0)

    1,0,0,0,
    1,1,1,1,
    1,1,1,1,
    1,1,1,1,

## Data Races

If not stated otherwise, concurrent invocation is not guaranteed to be thread-safe.

#### Dox Sources

    /*!
     * @fn transitiveClosure
     *
     * @headerfile <seqan/graph_algorithms.h>
     *
     * @brief Determines whether there is a path between any two given vertices or
     *        not.
     *
     * @signature void transitiveClosure(closure, g);
     *
     * @param[out] closure A matrix which indicates the closure. Entry (i,j) in this
     *                     matrix indicates whether there is a path from i to j in
     *                     the graph or not. Types: Matrix
     * @param[in] g A directed graph. Types: Directed Graph
     *
     * @section Example
     *
     * @include demos/dox/graph_algorithms/transitive_closure.cpp
     *
     * @include demos/dox/graph_algorithms/transitive_closure.cpp.stdout
     */