[r]
(1)program xoan_oc; uses crt;
var a:array[1 50,1 50] of integer; i,j,n,h,dem: integer;
begin clrscr;
write('nhap n: '); readln(n); for h:=1 to trunc(n div 2) begin
for j:=h to n-h begin
inc(dem); a[h,j]:=dem; end;
for i:=h to n-h begin
inc(dem);
a[i,n-h+1]:=dem; end;
for j:=n-h+1 downto h+1 begin
inc(dem);
a[n-h+1,j]:=dem; end;
for i:=n-h+1 downto h+1 begin
inc(dem); a[i,h]:=dem; end;
end;
{neu n chan thi vong lap tren se chay het tat ca cac vi tri
con ma n le thi khong chay toi duoc vi tri trung tam cua mang nen phai ep vao} if n mod 2<>0 then a[round(n/2),round(n/2)]:=n*n;
{in ra}
writeln('ket qua:'); for i:=1 to n begin
for j:=1 to n write(a[i,j]:4); writeln;