Initial data commit

Task/Dijkstras-algorithm/Raku/dijkstras-algorithm.raku

@@ -0,0 +1,80 @@
+class Graph {
+  has (%.edges, %.nodes);
+
+  method new(*@args){
+    my (%edges, %nodes);
+    for @args {
+      %edges{.[0] ~ .[1]} = $_;
+      %nodes{.[0]}.push( .[0] ~ .[1] );
+      %nodes{.[1]}.push( .[0] ~ .[1] );
+    }
+    self.bless(edges => %edges, nodes => %nodes);
+  }
+
+  method neighbours ($source) {
+    my (%neighbours, $edges);
+    $edges = self.nodes{$source};
+    for @$edges -> $x {
+      for self.edges{$x}[0..1] -> $y {
+        if $y ne $source {
+          %neighbours{$y} = self.edges{$x}
+        }
+      }
+    }
+    return %neighbours
+  }
+
+  method dijkstra ($source, $dest) {
+    my (%node_data, $v, $u);
+    my @q = self.nodes.keys;
+
+    for self.nodes.keys {
+      %node_data{$_}{'dist'} = Inf;
+      %node_data{$_}{'prev'} = '';
+    }
+    %node_data{$source}{'dist'} = 0;
+
+    while @q {
+      # %node_data.perl.say;
+      my ($mindist, $idx) =
+        @((map {[%node_data{@q[$_]}{'dist'},$_]},^@q).min(*[0]));
+      $u = @q[$idx];
+
+      if $mindist eq Inf {
+        return ()
+      }
+      elsif $u eq $dest {
+        my @s;
+        while %node_data{$u}{'prev'} {
+          @s.unshift($u);
+          $u = %node_data{$u}{'prev'}
+        }
+        @s.unshift($source);
+        return @s;
+      }
+      else {
+        @q.splice($idx,1);
+      }
+
+      for self.neighbours($u).kv -> $v, $edge {
+        my $alt = %node_data{$u}{'dist'} + $edge[2];
+        if $alt < %node_data{$v}{'dist'} {
+          %node_data{$v}{'dist'} = $alt;
+          %node_data{$v}{'prev'} = $u
+        }
+      }
+    }
+  }
+}
+
+my $a = Graph.new([
+  ["a", "b",  7],
+  ["a", "c",  9],
+  ["a", "f", 14],
+  ["b", "c", 10],
+  ["b", "d", 15],
+  ["c", "d", 11],
+  ["c", "f",  2],
+  ["d", "e",  6],
+  ["e", "f",  9]
+]).dijkstra('a', 'e').say;