打印 n*n 矩阵

本文转载自：http://www.iteye.com/topic/545378

一个画图程序 要求打印出n*n矩阵，如下：
（回旋数列）

引用

int i=6

1  2  3  4  5   6
20 21 22 23 24  7
19 32 33 34 25  8
18 31 36 35 26  9
17 30 29 28 27 10
16 15 14 13 12 11

class SnakePrint {
	static int length = 7;
	static int value = 1;
	static int[][] snake = new int[length][length];
	static Direction lastDirection = Direction.Right;

	static enum Direction {
		Right, Down, Left, Up;
	}

	public static void initialArray() {
		int row = 0, line = 0;
		for (int c = 0; c < length * length; c++) {
			snake[row][line] = value;
			lastDirection = findDirection(row, line);
			switch (lastDirection) {
				case Right:
					line++;
					break;
				case Down:
					row++;
					break;
				case Left:
					line--;
					break;
				case Up:
					row--;
					break;
				default:
					System.out.println("error");
			}
			value++;
		}
	}

	static Direction findDirection(int row, int line) {
		Direction direction = lastDirection;
		switch (direction) {
			case Right: {
				if ((line == length - 1) || (snake[row][line + 1] != 0))
					direction = Direction.Down;
				break;
			}
			case Down: {
				if ((row == length - 1) || (snake[row + 1][line] != 0))
					direction = Direction.Left;
				break;
			}
			case Left: {
				if ((line == 0) || (snake[row][line - 1] != 0))
					direction = Direction.Up;
				break;
			}
			case Up: {
				if (snake[row - 1][line] != 0)
					direction = Direction.Right;
				break;
			}
		}
		return direction;
	}

	public static void main(String[] args) {
		initialArray();

		// display.....
		for (int i = 0; i < length; i++) {
			for (int j = 0; j < length; j++) {
				System.out.print(snake[i][j] + "\t");
			}
			System.out.println();
		}
	}
}