public class 順時針輸出二維矩陣 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int[][]arr={
				 {1,2,2,3},
				 {4,5,4,6},
				 {7,8,6,9},
				 {1,2,3,4}
				 };
		int k=0;
		for(int i = 0; i < arr.length;i++){
			for(int j = 0;j < arr[0].length;j++){
				k++;
				System.out.print(arr[i][j]+" ");
				if(k % 4 == 0){
					System.out.println("");
				}
			}	
		}
		System.out.println("");
		System.out.println(arr[0].length);//列數(shù)
		
		System.out.println(arr.length);//行數(shù)	
		print(arr);
	}
	static void print (int[][]arr){
		int leftUpRow = 0;//最左行
		int leftUpCol = 0;//最左列
		int rightDownRow = arr.length-1;//最右列
		int rightDownCol = arr[0].length-1;//最右列
		while(leftUpRow <= rightDownRow && leftUpCol  <= rightDownCol){
			int row = leftUpRow, col = leftUpCol;
			//矩陣的第一行，此時行不變，列++
			while(col <= rightDownCol){
				System.out.print(arr[row][col++]+" ");
			}
			//矩陣右邊第一列  此時行++，列不變
			//將 col，row 恢復(fù)
			col = rightDownCol;
			row++;
			while(row <= rightDownRow){
				System.out.print(arr[row++][col]+" ");
			}
			//矩陣的最下面一行  此時 行不變 列--
			//還需要恢復(fù) col row 的值
			row = rightDownRow;
			col--;
			while(col >= leftUpCol){
				System.out.print(arr[row][col--]+" ");
			}
			//矩陣最左邊一列，此時行--，列不變
			//繼續(xù)恢復(fù) col row的值
			col = leftUpCol;
			row--;
			while(row > leftUpRow){
				System.out.print(arr[row--][col]+" ");
			}
			leftUpRow++;
			leftUpCol++;
			rightDownRow--;
			rightDownCol--;
		
		}
	}
}

1 2 2 3 
4 5 4 6 
7 8 6 9 
1 2 3 4 

1 2 2 3 6 9 4 3 2 1 7 4 5 4 6 8