CODE 74. Spiral Matrix II

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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 ]
]

public int[][] generateMatrix(int n) {
	// IMPORTANT: Please reset any member data you declared, as
	// the same Solution instance will be reused for each test case.
	int[][] matrix = new int[n][n];
	int number = 1;
	int halfCol = (n - 1) / 2;
	int halfRow = (n - 1) / 2;
	int col = 0;
	int row = 0;
	while (row <= halfRow && col <= halfCol) {
		for (int i = col; i < n - col; i++) {
			matrix[row][i] = number++;
		}
		for (int i = row + 1; i < n - row; i++) {
			matrix[i][n - col - 1] = number++;
		}
		if (row != n - row - 1) {
			for (int i = n - col - 2; i >= col; i--) {
				matrix[n - row - 1][i] = number++;
			}
		}

		if (col != n - col - 1) {
			for (int i = n - row - 2; i >= row + 1; i--) {
				matrix[i][col] = number++;
			}
		}
		row++;
		col++;
	}
	return matrix;
}