latinske_ctverce [Programování]

 
const N = 13;
type index = 1..N;
type pozice = 1..N*N;
var M: array[index, index] of 0..N;
 
function mozno (a, x, y: index): boolean;
var i: index;
begin
     mozno := true;
     for i := 1 to N do
         if (M[x, i] = a) or (M[i, y] = a) then
            mozno := false;
end;
 
procedure najdiCtverec (odkud: pozice);
var x, y:       index;
var i, j, k:    index;
begin
     if odkud > N*N then begin
        for i := 1 to N do begin
            for j := 1 to N do
                write (M[i, j]:3);
            writeln;
        end;
        writeln;
     end else begin
         x := (odkud - 1) mod N + 1;
         y := (odkud - 1) div N + 1;
         for k := 1 to N do begin
             if mozno (k, x, y) then begin
                M[x, y] := k;
                najdiCtverec (odkud + 1);
                M[x, y] := 0;
             end; {je-li mozno}
         end; {of for k}
     end; {of if}
end; {of najdiCtverec}
 
 
var i, j:   index;
begin
     for i := 1 to N do
         for j := 1 to N do
             M[i, j] := 0;
     najdiCtverec (1);
end.