spiral matrix

Outer spiral matrix– arrows are from boundary to core element. Inner Spiral matrix– Arrows are from core elements to boundary elements.

import java.util.*;     //for importing scanner class class spiral { public static void main(String args[]) { Scanner obj=new Scanner(System.in);   //can also be done by BufferReader. But then use: import.java.io.*; System.out.print("\nEnter the size of matrix (nxn):"); int n=obj.nextInt(); int a[][]=new int[n][n]; System.out.println("Your matrix is of order "+n+"x"+n+"\n"); int d,c,i,j,l,t,m,k; d=n-1; c=n*n+1;     // if its 3x3 matrix then 1-9 elements are filled. So c=10. afterwards --c making 9,8,.....1 for(i=;i<=(n+1)/2;i++) { for(j=i;j<=d;j++)   //first from west to east a[i][j]=--c; for(l=i+1;l<=d;l++)   //    north to south a[l][d]=--c; for(k=d-1;k>=i;k--)      //east to west a[d][k]=--c; for(m=d-1;m>i;m--)   //south to north a[m][i]=--c; d--;               // reducing the size of spiral } for(i=;i<n;i++) { for(j=;j<n;j++) System.out.print(a[i][j]+"\t"); System.out.println(); } } }