CODE 79. Spiral Matrix

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Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.
For example,
Given the following matrix:
[
[ 1, 2, 3 ],
[ 4, 5, 6 ],
[ 7, 8, 9 ]
]

You should return [1,2,3,6,9,8,7,4,5].

vector<int> spiralOrder(vector<vector<int> > &matrix) {
	// Note: The Solution object is instantiated only once and is reused by each test case.
	if(matrix.size() == 0){
		vector<int> spiralMatrix(0);
		return spiralMatrix;
	}
	int halfCol = (matrix[0].size() - 1) / 2;
	int halfRow = (matrix.size() - 1) / 2;
	int col = 0;
	int row = 0;
	vector<int> spiralMatrix(0);
	while(row <= halfRow && col <= halfCol){
		for(int i = col; i < matrix[0].size() - col; i++){
			spiralMatrix.push_back(matrix[row][i]);
		}
		for(int i = row + 1; i < matrix.size() - row; i++){
			spiralMatrix.push_back(matrix[i][matrix[0].size() - col - 1]);
		}
		if(row != matrix.size() - row - 1){
			for(int i = matrix[0].size() - col - 2; i >= col; i--){
				spiralMatrix.push_back(matrix[matrix.size() - row - 1][i]);
			}
		}

		if(col != matrix[0].size() - col){
			for(int i = matrix.size() - row - 2; i >= row + 1; i--){
				spiralMatrix.push_back(matrix[i][col]);
			}
		}

		row++;
		col++;
	}
	return spiralMatrix;
}