这是螺旋方阵啊,只有5阶,这里有个可以n阶的程序,没有过多解释,不过是方向数组,希望楼主能看懂：
const
dx:array[0..3] of longint=(0,1,0,-1);
dy:array[0..3] of longint=(1,0,-1,0);
var
a:array[0..21,0..21] of longint;
n,x,y,i,j,k,t:longint;
begin
readln(n);
for i:=0 to n+1 do
for j:=0 to n+1 do
a[i,j]:=1;
for i:=1 to n do
for j:=1 to n do
a[i,j]:=0;
x:=1;y:=1;
k:=0;
for t:=1 to n*n do
begin
a[x,y]:=t;
if a[x+dx[k],y+dy[k]]>0 then k:=(k+1) mod 4;
x:=dx[k]+x;
y:=dy[k]+y;
end;
for i:=1 to n do
begin
for j:=1 to n do
write(a[i,j]:5);
writeln;
end;
end.