Printing numbers in spiral shape

I need an algorithm for some program. I'll take some number (say 'n'), then i should print the numbers in spiral shape starting from square(n). Can any one pls help me..

Ex: if n=3, it should print like

9 8 7
2 1 6
3 4 5

Thanks in advance

p_n_lakshmi
Profile Answers by p_n_lakshmi Questions by p_n_lakshmi
Apr 30th, 2008
2
10424

Questions by p_n_lakshmi

Java

Answer

Showing Answers 1 - 2 of 2 Answers

Gerda
Profile Answers by Gerda

May 8th, 2008

One of possible solutions:

public class NumberSpiralShape {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub

int n = 3, i, side = n, x=0, y=0;int tab [][]= new int [n][n];

i=n*n;
while(i>=1){for(int j=0; j<side; j++)
tab[x][y++] = i--;
x++;
y--;
if(i>=1){for(int j=0; j<side-1; j++)
tab[x++][y] = i--;
x--;
y--;
}
if(i>=1){for(int j=0; j<side-1; j++)
tab[x][y--] = i--;
x--;
y++;
}
if(i>=1){for(int j=0; j<side-2; j++)
tab[x--][y] = i--;
y++;
x++;
side=side-2;
}
}
//print
for(i=0; i<n; i++){
for(int j=0; j<n; j++)System.
out.print(tab[i][j] + " ");System.out.println("n");
}
}
}

datdo
Profile Answers by datdo

Jan 29th, 2009

//spiral
//by datdo
//translated C code
public class Spiral {

int n =3;
public static int SPIRALHEIGHT = n;
public static int SPIRALWIDTH = n;

public static main(String[] args) {
   int matrix[SPIRALWIDTH][SPIRALHEIGHT];
   int c,r,rr, cc;
   int a = 0;
   cc = 0;
   rr = 0;
   for(c = 0; c < SPIRALHEIGHT; c++) {
       for(r = 0; r < SPIRALWIDTH; r++) {
           matrix[r][c] = 0;
       }
   }
   c =-1;
   r =-2;
   while(a < SPIRALWIDTH * SPIRALHEIGHT) {
       for(r+=2; r < SPIRALWIDTH -rr; r++) {
           matrix[r][c+1] = a;
           a++;
       }
       for(c+=2; c < SPIRALHEIGHT - cc; c++) {
           matrix[r - 1][c] = a;
           a++;
       }
       cc++;
       for(r-=2; r > rr-1 ; r--) {
           matrix[r][c - 1] = a;
           a++;
       }
       for(c-=2; c > cc-1 ; c--) {
           matrix[r+1][c] = a;
           a++;
       }
       rr++;
   }
   for(c = 0; c < SPIRALHEIGHT; c++) {
       for(r = 0; r < SPIRALWIDTH; r++) {
            System.out.print("%3d ", matrix[r][c]);
       }
        System.out.print("n");
   }
}