Graph colouring: Difference between revisions

* [[wp:Greedy coloring|Greedy coloring]] Wikipedia.

* [https://www.slideshare.net/PriyankJain26/graph-coloring-48222920 Graph Coloring : Greedy Algorithm & Welsh Powell Algorithm] by Priyank Jain.

 

=={{header|Go}}==

 

The results agree with the Python entry for examples 1 and 2 but, for example 3, Python gives 2 colors compared to my 4 and, for example 4, Python gives 3 colors compared to my 2.

 

import (

}

}

 

{{out}}

Number of colors : 2

</pre>

 

=={{header|Julia}}==

Uses a repeated randomization of node color ordering to seek a minimum number of colors needed.

 

"""Useful constants for the colors to be selected for nodes of the graph"""

prettyprintcolors(exgraph)

end

<pre>

Colors for the graph named Ex1:

</pre>

 

 

 

 

{{out}}

<pre>

 

=={{header|Python}}==

from collections import defaultdict

from itertools import count

]:

g = Graph(name, connections)

 

{{out}}

=={{header|Raku}}==

(formerly Perl 6)

my %OneMany = my %NodeColor;

for @RAW { %OneMany{$_[0]}.push: $_[1] ; %OneMany{$_[1]}.push: $_[0] }

say "Edges : ", $_.elems;

say "Colors : ", %out.values.Set.elems;

{{out}}

<pre>DATA : [(0 1) (1 2) (2 0) (3 NaN) (4 NaN) (5 NaN)]

Edges : 12

Colors : 2</pre>

 

=={{header|zkl}}==

numEdges,graph := 0,Dictionary(); // ( 0:(1,2), 1:L(0,2), 2:(1,0), 3:() )

foreach n in (nodeStr.split(" ")){ // parse string to graph

});

return(graph,colors,numEdges)

graph,colors,numEdges := colorGraph(graphStr);

nodes:=graph.keys.sort();

colors.values.pump(Dictionary().add.fp1(Void)).len()); // create set, count

println();

{{out}}

<pre style="height:45ex">