题目：
Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.
For example,
Given n = 3,
You should return the following matrix:
[ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ] ]
思路：
这题比I更容易，因为是完全的正方形
package array; public class SpiralMatrixII { public int[][] generateMatrix(int n) { int[][] matrix = new int[n][n]; int num = 0; for (int i = 0; i < n; ++i) { for (int j = i; j < n -i; ++j) { matrix[i][j] = ++num; } for (int j = i + 1; j < n -i; ++j) { matrix[j][n - i - 1] = ++num; } for (int j = n - i - 2; j >= i; --j) { matrix[n - i - 1][j] = ++num; } for (int j = n - i - 2; j >= i + 1; --j) { matrix[j][i] = ++num; } } return matrix; } public static void main(String[] args) { // TODO Auto-generated method stub SpiralMatrixII s = new SpiralMatrixII(); int n = 1; int[][] matrix = s.generateMatrix(n); for (int i = 0; i < n; ++i) { for (int j = 0; j < n; ++j) { System.out.print(matrix[i][j] + "\t"); } System.out.println(); } } }
原文：http://www.cnblogs.com/shuaiwhu/p/5079867.html