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;    }};