Shortest path

1 files changed, 42 insertions, 0 deletions

diff --git a/challenge-064/simon-proctor/raku/ch-1.raku b/challenge-064/simon-proctor/raku/ch-1.raku
new file mode 100644
index 0000000000..9228404924
--- /dev/null
+++ b/challenge-064/simon-proctor/raku/ch-1.raku
@@ -0,0 +1,42 @@
+#!/usr/bin/env raku
+
+use v6.d;
+
+#| Find the path from the top right of the grid to the
+#| Bottom left that sums up to the least amount.
+sub MAIN (
+    UInt $width, #= Width of the grid
+    *@cells where { $_.all ~~ UInt && 1 < $_.elems && $_.elems %% $width }, #= Cell values 
+    Bool :v(:$verbose) = False, #= Verbose mode
+) {
+    my @grid = @cells.rotor($width);
+    say "Width: $width\nGrid:" if $verbose;
+    say @grid.map( { .join(" ") } ).join("\n") if $verbose;
+
+    my @short-route = route-to( (0,0), (@grid[0].end,@grid.end) ).sort( -> @route { score-route( @grid, @route ) } )[0];
+    
+    @short-route[0].map( -> ($x,$y) { @grid[$y][$x] } ).join(" -> " ).say if $verbose;
+    
+    say score-route( @grid, @short-route[0] );
+}
+
+multi sub score-route( @grid, @route ) {
+    [+] @route.map( -> ( $x, $y ) { @grid[$y][$x] } );
+}
+
+multi sub route-to ( @s, @e where { @s ~~ @e } ) { return [ [@s,], ] }
+
+multi sub route-to( @s, @e ) {
+    my @routes;
+    if ( @s[0] !~~ @e[0] ) {
+        for route-to( ( @s[0]+1, @s[1] ), @e ) -> @route {
+            @routes.push( @route.unshift( @s ) );
+        }
+    }
+    if ( @s[1] !~~ @e[1] ) {
+        for route-to( ( @s[0], @s[1]+1 ), @e ) -> @route {
+            @routes.push( @route.unshift( @s ) );
+        }
+    }
+    @routes;
+}