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+#!env raku
+#
+# Perl Weekly Challenge 58
+#
+# Task 2
+#
+# Write a script to arrange people in a lineup according to how many taller people are in front of each person in line. You are given two arrays. @H is a list of unique heights, in any order. @T is a list of how many taller people are to be put in front of the corresponding person in @H. The output is the final ordering of people’s heights, or an error if there is no solution.
+
+#     Here is a small example:
+
+#     @H = (2, 6, 4, 5, 1, 3) # Heights
+#     @T = (1, 0, 2, 0, 1, 2) # Number of taller people in front
+
+#     The ordering of both arrays lines up, so H[i] and T[i] refer to the same person. For example,
+#     there are 2 taller people in front of     the person with height 4, and there is 1 person in front of the person with height 1.
+#
+# As per the last diagram, your script would then output the ordering (5, 1, 2, 6, 3, 4) in this case. (The leftmost element is the “front” of the array.)
+
+sub MAIN(){
+    my @H = 2, 6, 4, 5, 1, 3;
+    my @T = 1, 0, 2, 0, 1, 2;
+
+
+    # build an hash to map heights to tallers
+    my %HT;
+    for 0 ..^ @H.elems {
+        %HT{ @H[ $_ ] } = @T[ $_ ];
+    }
+
+
+    # evaluate all possible solutions
+    for %HT.keys.permutations -> @solution {
+        # the leftmost element must have a taller set to zero!
+        next if %HT{ @solution[ 0 ] } != 0;
+
+        # the solution is good if the number of tallers for
+        # every element is equal to the values of tallers
+        my $ok = True;
+
+        for 1 ..^ @solution.elems {
+            my $height  = @solution[ $_ ];
+            my $tallers = %HT{ $height };
+            $ok = False if @solution[ 0 .. $_-1].grep( * > $height ) != $tallers;
+            last if ! $ok;
+        }
+
+        say @solution if $ok;
+    }
+}