Prefixes

1 files changed, 44 insertions, 0 deletions

diff --git a/challenge-057/simon-proctor/raku/ch-2.p6 b/challenge-057/simon-proctor/raku/ch-2.p6
new file mode 100644
index 0000000000..f52bd713b4
--- /dev/null
+++ b/challenge-057/simon-proctor/raku/ch-2.p6
@@ -0,0 +1,44 @@
+#!/usr/bin/env raku
+
+use v6;
+
+#| Given a list of strings print the list of shortest unique prefixes
+sub MAIN (
+    *@words where *.elems >= 2
+) {
+    my @word-arrays = @words.map( *.comb );
+    my %result = prefix-hash( @word-arrays );
+    .say for traverse( %result );
+    
+}
+
+sub traverse ( %hash ) {
+    my @out;
+
+    for %hash.keys -> $key {
+        if ( %hash{$key} ~~ Hash ) {
+            my @res = traverse( %hash{$key} );
+            @out.push( [ $key, |$_] ) for @res;
+        } else {
+            @out.push( [ $key, ] );
+        }
+    }
+
+    return @out.map( *.join("") );
+}
+
+sub prefix-hash( @arrays ) {
+    my %hash;
+    
+    for @arrays -> [$key, *@rest] {
+        %hash{$key} //= [];
+        %hash{$key}.push( @rest );
+    }
+
+    for %hash.keys -> $key {
+        if %hash{$key}.elems > 1 {
+            %hash{$key} = prefix-hash( %hash{$key} );
+        }
+    }
+    return %hash;
+}