输入5和输入6输出效果如图：

java源代码如下：

package com.jiucaiyuan.recurse;



public class TestSquare {



	public static int a[][];

	

	public static void main(String[] args) {

		calc(5);

		print();

		System.out.println("===================================");

		calc(6);

		print();



	}

	

	private static void print() {

		if (a==null) return;

		for (int i=0;i<a.length;i++){

			for (int j=0;j<a[0].length;j++){

				System.out.print(a[i][j]+"\t");

			}

			System.out.println();

			System.out.println();

		}

		

	}









	public static int[][] calc(int lengthOfSide){

		

		if(lengthOfSide == 0){

			a = new int[][]{{0}};

			return a;

		}

		a = new int[lengthOfSide][lengthOfSide];

		int currValue = 1;

		int level =0;

		putValueToArray1(currValue,level);

		return a;

	}









	private static void putValueToArray1(int currValue,int level) {

		

		if (a.length%2==0){

			if (level == a.length/2-1){

				a[level][level] = currValue++;

				a[level][level+1] = currValue++;

				a[level+1][level+1] = currValue++;

				a[level+1][level] = currValue++;

				return;

			}

		}else{

			if (level == (a.length+1)/2 - 1){

				a[level][level] = currValue;

				return;

			}

		}

		

		//横向右

		for (int i=level;i<a.length - level;i++){

			a[level][i]=currValue;

			currValue++;

		}

		//竖向下

		for (int i=level+1;i<a.length-level;i++){

			a[i][a.length-level-1]=currValue;

			currValue++;

		}

		//横向左

		for (int i=a.length-level-2;i>level-1;i--){

			a[a.length-level-1][i]=currValue;

			currValue++;

		}

		//竖向上

		for (int i=a.length - level - 2;i>level ;i--){

			a[i][level]=currValue;

			currValue++;

		}

		

		putValueToArray1(currValue,level+1);

	}

	

	

	

	

}

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