Magic Square

odd_num(n)//creates magic square for odd number n
1.	[initialize segment variables] num=1 and  nn=n*3/2;
2.	Repeat  for i=0 to n
a.	Repeat for j=0 to n
i.	Set  m[(j-i+nn)%n][(i*2-j+n)%n]=num++;
3.	[End]

 even_num( n)//creates magic square for even number n
1.	[initialize segment variables] num:=1,  nminus:=n-1,nmiddle:=n/2,nn=n*n+1 and osl:=0.
2.	Set  first_block:=(n-2)/4, second_block=nminus-first_block.
3.	Set  first_inside=n/4, second_inside=nminus-first_inside.
4.	Repeat   for j=0 to n
a.	Repeat for i=0 to n
i.	If(i >= first_inside && i <= second_inside && j >= first_inside && j <= second_inside) then Set m[i][j]:=num.
ii.	else if((i > first_block && i < second_block) || (j > first_block && j < second_block)) then Set m[i][j]:= nn-num.
iii.	else  Set m[i][j]=num;
iv.	[Increase num].
5.	If(!(n%4))  then return;
6.	Set  switch_row[0]=random(nmiddle-1)+first_block+1;
7.	Set  switch_row[1]=random(nmiddle-1);
8.	If(switch_row[1] >= first_block) then Set  switch_row[1]+=(nmiddle+1);
9.	Set last_switch_column=random(nmiddle-1);
10.	If(last_switch_column >= first_block) then Set  last_switch_column+=(nmiddle+1);
11.	Repeat for i=0 to nmiddle
a.	If(i==first_block || i==second_block) then:
i.	Set osl=1-osl and continue.
b.	CALL  swap(second_block, i, second_block, nminus-i);
c.	CALL  swap(i, first_block, nminus-i, first_block);
d.	CALL  swap(i, second_block, nminus-i, second_block);
e.	CALL  swap(i, switch_row[osl], nminus-i, switch_row[osl]);
12.	Repeat for i=first_block+1 to i < second_block
a.	CALL  swap(first_block, i, second_block, i);
b.	CALL  swap(i, first_block, i, second_block);
13.	CALL   swap(first_block, nmiddle, second_block, nmiddle);
14.	CALL    swap(last_switch_column, first_block, last_switch_column, second_block);
15.	[end]

swap( i1, j1,i2, j2)//swaps values at mi1j1 with value at mi2j2
1.	[interchange m[i1][j1] with m[i2][j2]
a.	Set  k := m[i1][j1];
b.	Set  m[i1][j1]=m[i2][j2];
c.	Set  m[i2][j2]=k;
2.	[end]

/*Magic Box Problem*/
import java.io.*;
class magic
{
      public static void main(String args[])throws IOException
      {
             int n,i,j,k,nsqr;
             System.out.println("Enter the order of matrix");
             BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
             n=Integer.parseInt(br.readLine());
             nsqr=n*n;
             int a[][]=new int[n][n];
             i=0;
             j=n/2;
             for(k=1;k<=nsqr;k++)
             {
                   a[i][j]=k;
                   i--;
                   j++;
                   if(k%n==0)
                   {
                        i+=2;
                        j--;
                   }
                   else if(j==n)
                        j-=n;
                   else if(i<0)
                        i+=n;
               }
               System.out.println("The resultant magic box is:");
               for(i=0;i<n;i++)
               {
                 System.out.print("\n");
                   for(j=0;j<n;j++)
                      System.out.print("     "+ a[i][j]);
               }  
         }
}