LeetCode 59 Spiral Matrix II

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 ]
]

从最外圈到最内圈，一圈一圈写矩阵，最后对矩阵最中心的数据进行处理。

public int[][] generateMatrix(int n) {
int[][] matrix = new int

;
int count = 1;
int begin = 0, end = n - 1;
while (begin > end) {
for (int i = begin; i < end; i++) matrix[begin][i] = count++;
for (int i = begin; i < end; i++) matrix[i][end] = count++;
for (int i = end; i > begin; i--) matrix[end][i] = count++;
for (int i = end; i > begin; i--) matrix[i][begin] = count++;
begin++;
end--;
}
if (begin==end) matrix[begin][end]=count;
return matrix;
}