Spiral Matrix II (Java)

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 ]]

在spiral matrix那道题上稍微改动一下就可以通过

Source

 public int[][] generateMatrix(int n) {        int[][] matrix = new int[n][n];  //填数的话尺寸要确定到第二维    if(n == 0) return matrix;        int cycle = n / 2;    int p = 1;            for(int i = 0; i < cycle; i++){   //***    for(int j = i; j < n - i; j++){    matrix[i][j] = p++;    }    for(int j = i + 1; j < n - i; j++){    matrix[j][n - 1 - i] = p++;    }    for(int j = n - i - 2; j >= i; j--){    matrix[n - 1 - i][j] = p++;    }    for(int j = n - 2 - i; j > i; j--){    matrix[j][i] = p++;    }    }    if(p <= n * n){//奇数行   注意只有一行和一列的情况    for(int j = cycle ; j < n - cycle ; j++){    matrix[cycle][j] = p++;    }    for(int j = cycle + 1; j < n - cycle; j++){    matrix[j][cycle] = p++;    }        }    return matrix;    }

Test

    public static void main(String[] args){        int n = 3;    int[][] st = new Solution().generateMatrix(n);    for(int i = 0; i < st.length; i++){    for(int j = 0; j < st[0].length; j++){    System.out.print(st[i][j] + " ");  //打空格注意用双引号，用单引号容易转换为char相加后的数值    }    }            }