Magic squares of doubly even order: Difference between revisions

=={{header|Phix}}==

{{trans|C++}}

<lang Phix>constant t = {{1,0,0,1},

{0,1,1,0},

{0,1,1,0},

{1,0,0,1}}

function magic_square(integer n)

if n<4 or mod(n,4)!=0 then return false end if

sequence square = repeat(repeat(0,n),n)

integer i = 0

for r=1 to n do

for c=1 to n do

square[r,c] = iff(t[mod(r-1,4)+1,mod(c-1,4)+1]?i+1:n*n-i)

i += 1

end for

end for

return square

end function

procedure check(sequence sq)

integer n = length(sq)

integer magic = n*(n*n+1)/2

integer bd = 0, fd = 0

for i=1 to length(sq) do

if sum(sq[i])!=magic then ?9/0 end if

if sum(columnize(sq,i))!=magic then ?9/0 end if

bd += sq[i,i]

fd += sq[n-i+1,n-i+1]

end for

if bd!=magic or fd!=magic then ?9/0 end if

end procedure

--for i=4 to 16 by 4 do

for i=8 to 8 by 4 do

sequence square = magic_square(i)

printf(1,"maqic square of order %d, sum: %d\n", {i,sum(square[i])})

string fmt = sprintf("%%%dd",length(sprintf("%d",i*i)))

pp(square,{pp_Nest,1,pp_IntFmt,fmt,pp_StrFmt,1,pp_Pause,0})

check(square)

end for</lang>

{{out}}

<pre>

maqic square of order 8, sum: 260

{{ 1,63,62, 4, 5,59,58, 8},

{56,10,11,53,52,14,15,49},

{48,18,19,45,44,22,23,41},

{25,39,38,28,29,35,34,32},

{33,31,30,36,37,27,26,40},

{24,42,43,21,20,46,47,17},

{16,50,51,13,12,54,55, 9},

{57, 7, 6,60,61, 3, 2,64}}

</pre>