Spiral Matrix

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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:

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2
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5
[
 [ 1, 2, 3 ],
 [ 4, 5, 6 ],
 [ 7, 8, 9 ]
]

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

定义运动方向，使用状态来解决这个问题，注意坐标的计算即可。

AC代码：

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class Solution {
public:
    vector<int> spiralOrder(vector<vector<int>>& matrix) {
		vector<int> result;
		int row = matrix.size();
		int col = 0;

		if (row != 0)
		{
			col = matrix[0].size();
		}

		if (col * row == 0)
		{
			return result;
		}

		int ri = 0;
		int ci = 0;
		bool left = false;
		bool right = true;
		bool up = false;
		bool down = false;
		int br = 0, er = row - 1;
		int bc = 0, ec = col - 1;

		while (result.size() != col * row)
		{
			result.push_back(matrix[ri][ci]);
			if (!left && right && !up && !down)
			{
				if (ci == ec)
				{
					ci = ec;
					right = false;
					down = true;
					br++;
					ri++;
				}
				else
				{
					ci++;
				}
			}
			else if (left && !right && !down && !up)
			{
				if (ci == bc)
				{
					ci = bc;
					left = false;
					up = true;
					er--;
					ri--;
				}
				else
				{
					ci--;
				}
			}
			else if (!left && !right && down && !up)
			{
				if (ri >= er)
				{
					ri = er;
					down = false;
					left = true;
					ec--;
					ci--;
				}
				else
				{
					ri++;
				}
			}
			else
			{
				if (ri <= br)
				{
					ri = br;
					up = false;
					right = true;
					bc++;
					ci++;
				}
				else
				{
					ri--;
				}
			}
		}
		return result;
    }
};