CUFP YuckFoo Here's a little ditty to put your birthday in the corners of a 4 x 4 magic square. In a magic square, the sum of all columns, all rows, and the two major diagonals is the same. <p> The squares made with this algorithm also have same values in the corner 2 x 2 squares, and the center 2 x 2 square. <p> The square has the maximum number of unique values allowed by the algorithm. I didn't devise a clever way to disallow negative numbers so folks with low birthmonth or birthday might see negative values. There is a random factor, so running the program again might generate an all positive square. <p> SquareFoo <p> <code> #!/usr/bin/perl use strict; if (@ARGV < 1) { print STDERR "\nUsage: \$0 mmddyyyy\n\n"; exit; } my (\$mm, \$dd, \$cc, \$yy) = (\$ARGV =~ m{(..)}g); my \$ms = []; \$ms-> = [\$mm, \$cc, \$yy, \$dd]; \$ms-> = [\$yy, \$dd, \$mm, \$cc]; \$ms-> = [\$dd, \$yy, \$cc, \$mm]; \$ms-> = [\$cc, \$mm, \$dd, \$yy]; my \$most = 12 + uniq(\$ms); if (\$mm == \$dd) { \$most--; } if (\$mm == \$cc) { \$most--; } if (\$yy == \$dd) { \$most--; } if (\$yy == \$cc) { \$most--; } while (uniq(\$ms) < \$most) { if (int(rand(2))) { if (int(rand(2))) { rot (\$ms, 1, 0, 1); rot (\$ms, 1, 2, -1); } else { rot (\$ms, 1, 0, -1); rot (\$ms, 1, 2, 1); } } else { if (int(rand(2))) { rot (\$ms, 0, 1, 1); rot (\$ms, 2, 1, -1); } else { rot (\$ms, 0, 1, -1); rot (\$ms, 2, 1, 1); } } } show (\$ms); #----------------------------------------------------------- sub uniq { my (\$ms) = @_; my (%used); for my \$row (0..3) { for my \$col (0..3) { \$used{\$ms->[\$row][\$col]}++; } } return scalar(keys(%used)); } #----------------------------------------------------------- sub rot { my (\$ms, \$row, \$col, \$val) = @_; \$ms->[\$row] [\$col] += \$val; \$ms->[\$row+1][\$col+1] += \$val; \$ms->[\$row] [\$col+1] -= \$val; \$ms->[\$row+1][\$col] -= \$val; } #----------------------------------------------------------- sub show { my (\$ms) = @_; for my \$row (0..3) { for my \$col (0..3) { printf(STDOUT "%2d ", \$ms->[\$row][\$col]); } print STDOUT "\n"; } } </code>