Add TWC 251 solutions by Bruce Gray (in Raku and Scala).

4 files changed, 177 insertions, 0 deletions

diff --git a/challenge-251/bruce-gray/raku/ch-1.raku b/challenge-251/bruce-gray/raku/ch-1.raku
new file mode 100644
index 0000000000..62fbe9c8c7
--- /dev/null
+++ b/challenge-251/bruce-gray/raku/ch-1.raku
@@ -0,0 +1,62 @@
+sub task1a ( @ns --> Numeric ) {
+    my $half = +@ns div 2;
+    my $odd  = +@ns !%% 2;
+
+    my @left   = @ns.head($half);
+    my $middle = @ns.skip($half)[0] if $odd;
+    my @right  = @ns.skip($half + (1 if $odd));
+
+    return (@left »~« @right.reverse).sum + ($middle // 0);
+}
+sub task1b ( @ns --> Numeric ) {
+    my @r = @ns;
+    my @l = @r.splice(0, * div 2);
+    my $m = @r.splice(0,   1)[0] if @ns % 2;
+
+    die "Cannot happen" if +@l != +@r;
+
+    return (@l »~« @r.reverse).sum
+         + ($m // 0);
+}
+sub task1c ( @ns --> Numeric ) {
+    return (@ns.head(@ns/2) »~« @ns.tail(@ns/2).reverse).sum
+         + (@ns.skip(@ns/2)[0] if @ns % 2);
+}
+sub task1d ( @ns_in --> Numeric ) {
+    my @ns = @ns_in;
+
+    my $ret = 0;
+    $ret += @ns.shift ~ @ns.pop while @ns > 1;
+    $ret += @ns.shift              if @ns;
+
+    return $ret;
+}
+sub task1e ( @ns --> Numeric ) {
+    my ($i, $j) = 0, @ns.end;
+
+    my $ret = 0;
+    $ret += @ns[$i++, $j--].join while $i <  $j;
+    $ret += @ns[$i]                 if $i == $j;
+
+    return $ret;
+}
+
+my @subs =
+    :&task1a,
+    :&task1b,
+    :&task1c,
+    :&task1d,
+    :&task1e,
+;
+my @tests =
+    ( 1286, (  6, 12, 25, 1 ) ),
+    (  489, ( 10,  7, 31, 5, 2, 2 ) ),
+    (  112, (  1,  2, 10 ) ),
+    (    0, [] ),
+;
+use Test; plan +@tests * @subs;
+for @subs -> ( :key($sub_name), :value(&task1) ) {
+    for @tests -> ( $expected, @in ) {
+        is task1(@in), $expected, "$sub_name : $expected";
+    }
+}
diff --git a/challenge-251/bruce-gray/raku/ch-2.raku b/challenge-251/bruce-gray/raku/ch-2.raku
new file mode 100644
index 0000000000..8346d47756
--- /dev/null
+++ b/challenge-251/bruce-gray/raku/ch-2.raku
@@ -0,0 +1,28 @@
+sub task2 ( @in --> Numeric ) {
+    # Prevents recalculation inside `.first`
+    my @column_maxes = @in[0].keys.map({ @in».[$_].max });
+
+    for @in -> @row {
+        return .value with @row.minpairs.first: { @column_maxes[.key] == .value };
+    }
+    return -1;
+}
+
+
+my @tests =
+    ( 15, ( ( 3,  7,  8    ), ( 9, 11, 13    ), (15, 16, 17    ) ) ),
+    ( 12, ( ( 1, 10,  4,  2), ( 9,  3,  8,  7), (15, 16, 17, 12) ) ),
+    (  7, ( ( 7,  8        ), ( 1,  2        )                   ) ),
+
+    (  3, ( ( 3,  3,  3    ), ( 3,  9,  9    ), ( 3, 3, 3    ) ) ),
+    
+    (  3, ( ( 9,  3, 15    ), ( 9,  3, 15    ), ( 9, 3, 15    ) ) ),
+
+    ( -1, ( ( 1, 5, 8 ), ( 2, 6, 4 ), ( 7, 3, 9 ) ) ),
+
+    ( -1, ( (0, 1, 2), (1, 2, 0), (2, 0, 1) ) ),
+;
+use Test; plan +@tests;
+for @tests -> ( $expected, @in ) {
+    is task2(@in), $expected;
+}
diff --git a/challenge-251/bruce-gray/scala/ch-1.scala b/challenge-251/bruce-gray/scala/ch-1.scala
new file mode 100644
index 0000000000..032f375379
--- /dev/null
+++ b/challenge-251/bruce-gray/scala/ch-1.scala
@@ -0,0 +1,42 @@
+// Run with `scala scala/ch-1.scala`
+val task1 = ( ns: Array[Int] ) =>
+    var i = 0
+    var j = ns.length - 1
+    var ret = 0
+
+    while ( i <  j ) {
+        ret += s"${ns(i)}${ns(j)}".toInt
+        i += 1
+        j -= 1
+    }
+
+    if i == j then
+        ret += ns(i)
+
+    ret
+
+
+// Below this point is test harness and data
+var test_number = 0
+val is = ( got:Int, expected:Int, test_name:String ) =>
+    test_number += 1
+    val ok_msg = if (got == expected) then "ok" else "not ok"
+    println(s"$ok_msg $test_number $test_name")
+
+@main def TWC251_1(args: String*): Unit = {
+    if (args.length > 0) {
+        println(task1(args.map(_.toInt).toArray))
+    }
+    else {
+        val arr = List(
+            ( 1286, Array( 6, 12, 25, 1)       , "Task example 1" ),
+            (  489, Array(10,  7, 31, 5, 2, 2) , "Task example 2" ),
+            (  112, Array( 1,  2, 10)          , "Task example 3" ),
+            (    0, Array[Int]()               , "Empty --> 0"    )
+        )
+
+        for (((expected, in, test_name)) <- arr) {
+            is( task1( in ), expected, test_name )
+        }
+    }
+}
diff --git a/challenge-251/bruce-gray/scala/ch-2.scala b/challenge-251/bruce-gray/scala/ch-2.scala
new file mode 100644
index 0000000000..ae19ab47eb
--- /dev/null
+++ b/challenge-251/bruce-gray/scala/ch-2.scala
@@ -0,0 +1,45 @@
+// Run with `scala scala/ch-2.scala`
+val task2 = ( matrix: List[List[Int]] ) =>
+
+    val column_maxes = matrix(0).indices.map(j => {
+        matrix.map{_(j)}.max
+    })
+
+    var ret = -1
+    import scala.util.control.Breaks._
+    breakable {
+        for (row <- matrix) {
+            // Minimums can occur more than once in a row
+            val min_col_value = row.min
+            val min_col_indexes = row.indices.filter(j => row(j) == min_col_value)
+
+            if ( min_col_indexes.exists(j => min_col_value == column_maxes(j)) ) {
+                ret = min_col_value
+                break
+            }
+        }
+    }
+    ret
+
+
+// Below this point is test harness and data
+var test_number = 0
+val is = ( got:Int, expected:Int, test_name:String ) =>
+    test_number += 1
+    val ok_msg = if (got == expected) then "ok" else "not ok"
+    println(s"$ok_msg $test_number $test_name")
+
+@main def TWC251_2(): Unit = {
+    val arr = List(
+        ( 15, List( List( 3,  7,  8    ), List( 9, 11, 13    ), List(15, 16, 17    ) ), "Task example 1" ),
+        ( 12, List( List( 1, 10,  4,  2), List( 9,  3,  8,  7), List(15, 16, 17, 12) ), "Task example 2" ),
+        (  7, List( List( 7,  8        ), List( 1,  2        )                       ), "Task example 3" ),
+        (  3, List( List( 3,  3,  3    ), List( 3,  9,  9    ), List( 3, 3, 3      ) ), "3&9" ),
+        (  3, List( List( 9,  3, 15    ), List( 9,  3, 15    ), List( 9, 3, 15     ) ), "3,9,15" ),
+        ( -1, List( List( 1,  5,  8    ), List( 2,  6,  4    ), List( 7, 3, 9      ) ), "-1"  ),
+    )
+
+    for (((expected, in, test_name)) <- arr) {
+        is( task2(in), expected, test_name )
+    }
+}