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].

class Solution {
public:
    vector<int> spiralOrder(vector<vector<int> > &matrix) {
        vector<int> result;
        if (matrix.size() == 0)
        {
            return result;
        }
        int left = 0;
        int top = 0;
        int bottom = matrix.size() - 1;
        int right = matrix[0].size() - 1;
        int row = 0;
        int column = 0;
        while (left <= right && top <= bottom)
        {
            if (column <= right)
            {
                while (column <= right)
                {
                    result.push_back(matrix[row][column]);
                    column++;
                }
                column--;
                top++;
                row++;
            }

            if (left <= right && top <= bottom && row <= bottom)
            {
                while (row <= bottom)
                {
                    result.push_back(matrix[row][column]);
                    row++;
                }
                row--;
                right--;
                column--;
            }

            if (left <= right && top <= bottom && column >= left)
            {
                while (column >= left)
                {
                    result.push_back(matrix[row][column]);
                    column--;
                }
                column++;
                bottom--;
                row--;
            }

            if (left <= right && top <= bottom && row >= top)
            {
                while (row >= top)
                {
                    result.push_back(matrix[row][column]);
                    row--;
                }
                row++;
                left++;
                column++;
            }
        }

        return result;
    }
};