Spiral Matrix 1&2

1.

Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.

For example,
Given the following matrix:

[
 [ 1, 2, 3 ],
 [ 4, 5, 6 ],
 [ 7, 8, 9 ]
]

You should return [1,2,3,6,9,8,7,4,5].

2.Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.

package leetcode2;

import java.util.*;

public class SpiralMatrix {
     public static ArrayList<Integer> spiralOrder(int[][] matrix) {
         ArrayList<Integer> res=new ArrayList<Integer>();
           if(matrix==null||matrix.length==0){
               return res;
           }
           int m=matrix.length;
           int n=matrix[0].length;     
           int x=0;
           int y=0;
           while(n>0 && m>0){
             if(m==1){
               for(int i=0;i<n;i++){
                   res.add(matrix[x][y++]);
               }
               break;
             }else  if(n==1){
                 for(int i=0;i<m;i++){
                       res.add(matrix[x++][y]);
                   } 
                 break;
             }
             
             for(int i=0;i<n-1;i++){
                   res.add(matrix[x][y++]);
               } 
             for(int i=0;i<m-1;i++){
                   res.add(matrix[x++][y]);
               }
             for(int i=0;i<n-1;i++){
                   res.add(matrix[x][y--]);
               } 
             for(int i=0;i<m-1;i++){
                   res.add(matrix[x--][y]);
               }
             x++;
             y++;
             n=n-2;
             m=m-2;

           }
           return res;
        }
     /*
      * SpiralMatrix2
      *   public int[][] generateMatrix(int n) {
        int[][] res=new int[n][n];
        int top=0;
        int left=0;
        int botton=n-1;
        int right=n-1;
        int k=1;
        while(top<botton&&left<right){
            for(int i=left;i<right;i++){
                res[top][i]=k++;
            }
            for(int i=top;i<botton;i++){
                res[i][right]=k++;
            }
            for(int i=right;i>left;i--){
                res[botton][i]=k++;
            }
            for(int i=botton;i>top;i--){
                res[i][left]=k++;
            }
            left++;
            right--;
            top++;
            botton--;
        }
        if(n%2!=0){
            res[n/2][n/2]=k;
        }
        return res;
    }
      */
    public static void main(String[] args) {
        // TODO Auto-generated method stub

    }

}