java顺时针、逆时针打印矩阵

题目要求：

顺时针打印一个数组，比如输入3，打印出：

首先我们来分析一下这个数组，如下图所示,数组的是沿着顺时针的方向按照数字递增的方式增加的，我们一般是使用for嵌套来构造这个数组。但这样结构还臃肿了，而且也不好设计。最新开始也是这样想的，但发现这样的方式不是最优雅的！！

比如楼主看到的一个案例。

虽然博主写得很详细，说实在看着头就痛。为了能写得更优雅，楼主在网上找到了一个方案，然后理解后修改了一下。自我感觉这种方案比较好理解，也不要一个一个的嵌入for。

分析：数组每次都会依次填入，但每次到边界时就自动换方向。第一次向右，到边界时马上变为向下，到了下边界然后再向左，同理到了左边界再向上。所以我们可以定义一个方向的enum。然后在根据每次的转换变方向。源码如下：

import java.util.*;
public class SnakeMatrix{
/**
* 定义矩阵的阶数
*/
private int n;

//填充矩阵的值
private int k = 1;

private int[][] data;
/**
*定义矩阵移动的方向
*/
public enum Direction{
left,right,up,down,
}

SnakeMatrix(int n){
this.n = n;
data = new int

;
}

public void clockwisePrintMatrix(){
//定义行数
int rowLen = data.length;

//定义列数
int columnLen = data.length;

//移动方向
Direction direction=Direction.right;

//定义上边界
int upBound = 0;

//定义下边界
int downBound = rowLen - 1;

//定义左边界
int leftBound = 0;

//定义右边界
int rightBound = columnLen -1;

//矩阵当前行数
int row = 0;

//矩阵当前列数
int column = 0;

while(true){
data[row][column] = k++;
if(upBound==downBound&&leftBound==rightBound){
//  System.out.println(" upBound :"+upBound +" downBound :"+downBound+" leftBound :"+leftBound +" rightBound :"+rightBound);
break;
}
switch (direction){
case right:
if(column<rightBound){
++column;
}else{
++row;
direction=Direction.down;
++upBound;
}
break;
case down:
if(row<downBound){
++row;
}else{
--column;
direction=Direction.left;
--rightBound;
}
break;
case up:
if(row>upBound){
--row;
}else{
++column;
direction=Direction.right;
++leftBound;
}
break;
case left:
if(column>leftBound){
--column;
}else{
--row;
direction=Direction.up;
--downBound;
}
break;
default:break;
}

}

for (int i= 0;i<n ; i++) {
for (int j = 0; j<n;j++ ) {
System.out.printf("%2d%s",data[i][j]," ");
}
System.out.println();

}
}

public void anticlockwisePrintMatrix(){

int rowLen = data.length;

int columnLen = data.length;

int leftBound = 0;

int rightBound = columnLen - 1;

int upBound = 0;

int downBound =rowLen - 1;

int row = 0;

int column = 0;

Direction direction = Direction.down;

while(true){

data[row][column] = k++;

if(rightBound == leftBound && upBound == downBound){
break;
}

switch(direction){

case down:
if(row < downBound){
row++;
}else{
column++;
direction = Direction.right;
leftBound++;
}
break;
case right:
if(column < rightBound){
column++;
}else{
row--;
direction = Direction.up;
downBound--;
}
break;
case up:
if(row > upBound){
row--;
}else{
direction = Direction.left;
column--;
rightBound--;
}
break;
case left:
if(column > leftBound){
column--;
}else{
direction = Direction.down;
row++;
upBound++;
}
break;
default:break;
}

}

for (int i= 0;i<n ; i++) {
for (int j = 0; j<n;j++ ) {
System.out.printf("%2d%s",data[i][j]," ");
}
System.out.println();
}

}

public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("请输入阶数: ");
int number = scanner.nextInt();
SnakeMatrix snakeMatrix = new SnakeMatrix(number);
//snakeMatrix.anticlockwisePrintMatrix();
snakeMatrix.clockwisePrintMatrix();
}

}

其中添加了逆时针打印。效果图如下: