CODE 79: Spiral Matrix

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;
	}