⚠️ Warning: This is a draft ⚠️

This means it might contain formatting issues, incorrect code, conceptual problems, or other severe issues.

If you want to help to improve and eventually enable this page, please fork RosettaGit's repository and open a merge request on GitHub.

Rather than having multiple examples for different orders of magic square, this will generate a magic square for ''any'' valid n x n grid.

Invoke at the command line and pass in the desired size as a parameter.

{{works with|Rakudo|2016-02}}

See:

• [[Magic_squares_of_odd_order#Perl_6|Magic squares of odd order#Perl 6]]
• [[Magic_squares_of_singly_even_order#Perl_6|Magic squares of singly even order#Perl 6]]
• [[Magic_squares_of_doubly_even_order#Perl_6|Magic squares of doubly even order#Perl 6]]
```sub MAIN (Int \$n where {\$n > 0}) {

my @sq;
my \$i = 1;
my \$h = \$n div 2;
my \$q = \$n div 4;

gen-sq(\$n);

say .fmt("%{\$i.chars}d", ' ') for @sq;

say "\nThe magic number is ", [+] @sq[0].list;

multi sub gen-sq (2) { # invalid
note "Sorry, can not generate a 2 x 2 magic square." and exit;
}

multi sub gen-sq (\$n where {\$n % 2}) { # odd
my \$x = \$n/2;
my \$y = 0;
@sq[(\$i % \$n ?? \$y-- !! \$y++) % \$n][(\$i % \$n ?? \$x++ !! \$x) % \$n] = \$i++ for ^\$n²;
}

multi sub gen-sq (\$n where {\$n %% 4}) { # doubly even
my \$x = 0;
my \$y = 0;
@sq[\$i % \$n ?? \$y !! \$y++][(\$i-1) % \$n] = \$i++ for ^\$n²;
for ^\$q -> \$r {
for \$q ..^ \$n - \$q -> \$c {
my \$ŕ = \$n - 1 - \$r;
my \$ć = \$n - 1 - \$c;
(@sq[\$r;\$c], @sq[\$ŕ;\$ć]) = (@sq[\$ŕ;\$ć], @sq[\$r;\$c]);
(@sq[\$c;\$r], @sq[\$ć;\$ŕ]) = (@sq[\$ć;\$ŕ], @sq[\$c;\$r]);
}
}
}

multi sub gen-sq (\$n where {\$n %% 2 and \$n % 4}) { # singly even
gen-sq(\$h);
\$i *= 4;
for ^\$h -> \$r {
for ^\$h -> \$c {
@sq[\$r + \$h; \$c]      = @sq[\$r;\$c] + \$h² * 3;
@sq[\$r; \$c + \$h]      = @sq[\$r;\$c] + \$h² * 2;
@sq[\$r + \$h; \$c + \$h] = @sq[\$r;\$c] + \$h²;
}
for ^\$q -> \$c {
next if \$c == 0 and \$r == (\$h-1) div 2;
(@sq[\$r;\$c], @sq[\$r + \$h;\$c]) = (@sq[\$r + \$h;\$c], @sq[\$r;\$c]);
}
if \$h > 4 {
for (\$n - \$q + 1) ..^ \$n -> \$c {
(@sq[\$r;\$c], @sq[\$r + \$h;\$c]) = (@sq[\$r + \$h;\$c], @sq[\$r;\$c]);
}
}
}
(@sq[\$q;\$q], @sq[\$q+\$h;\$q]) = (@sq[\$q+\$h;\$q], @sq[\$q;\$q]);
}
}
```