LeedCode_螺旋矩阵

LeedCode_螺旋矩阵

题目说明

给定一个包含 m x n 个元素的矩阵（m 行, n 列），请按照顺时针螺旋顺序，返回矩阵中的所有元素。

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

链接：https://leetcode-cn.com/problems/spiral-matrix
分析：常规的思路，设置上下左右边界

vector<int> spiralOrder(vector<vector<int>>& matrix) 
{
	vector<int> ans;
	int row = matrix.size();
	if (row == 0)
	{
		return ans;
	}
	int col = matrix[0].size();
	int left = 0, right = col - 1;
	int top = 0, bottom = row - 1;
	while (true)
	{
		for (int i = left; i <= right; i++)
		{
			ans.push_back(matrix[top][i]);
		}
		top++;
		if (top > bottom)
			break;
		for (int i = top; i <=bottom; i++)
		{
			ans.push_back(matrix[i][right]);
		}
		right--;
		if (right < left)
			break;
		for (int i = right; i >= left; i--)
		{
			ans.push_back(matrix[bottom][i]);
		}
		bottom--;
		if (bottom < top) break;
		for (int i = bottom; i >= top; i--)
		{
			ans.push_back(matrix[i][left]);
		}
		left++;
		if (left > right)
			break;
	}
	return ans;
}