leetcode-java-59. Spiral Matrix II

/*Given an integer n, generate a square matrix filled with elements from 1 to n^2in spiral order.For example, Given n = 3,You should return the following matrix: [ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ]] */ public class Solution {     public int[][] generateMatrix(int n) {         int[][] matrix = new int[n][n];         int maxLoop = (n+1)/2,             begin = 1;         for(int i = 0;i < maxLoop;i++) {             // (i,i)--(i,n-1-i)             for(int j = i;j <= n-1-i;j++) {                 matrix[i][j] = begin++;             }             // (i+1,n-1-i)--(m-1-i,n-1-i)             for(int j = i+1;j <= n-1-i;j++) {                 matrix[j][n-1-i] = begin++;             }             // (m-1-i,n-i-2)--(m-1-i,i)             if(n-1-i > i) {                 for(int j = n-i-2;j >= i;j--) {                     matrix[n-1-i][j] = begin++;                 }             }             // (m-i-2,i)--回到(i,i)             if(n-1-i > i) {                for(int j = n-i-2;j > i;j--) {                     matrix[j][i] = begin++;                 }             }         }         return matrix;     } }