sub merge_sort { my @x = @_; return @x if @x < 2; my $m = int @x / 2; my @a = merge_sort(@x[0 .. $m - 1]); my @b = merge_sort(@x[$m .. $#x]); for (@x) { $_ = !@a ? shift @b : !@b ? shift @a : $a[0] <= $b[0] ? shift @a : shift @b; } @x; } my @a = (4, 65, 2, -31, 0, 99, 83, 782, 1); @a = merge_sort @a; print "@a\n";