顺时针打印矩阵

题目：

输入一个矩阵，按照从外向里以顺时针的顺序依次打印出每一个数字。

如：

输入矩阵： 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

依次打印出数字 1,2,3,4,8,12,16,15,14,13,9,5,6,7,11,10.

• 难点：怎么判断是否为最后一行

#include<iostream>
#include<vector>
using namespace std;


class Solution {
public:
	vector<int> printMatrix(vector<vector<int> > matrix) {

		int row = matrix.size();  //行
		int col = matrix[0].size();//列
		int top = 0, left = 0;//矩阵的左上角
		vector<int>res;
		//矩阵为空
		if (row == 0 || col == 0)
			return res;
		int right = col - 1, bottom = row - 1;
		while (bottom >= top && right >= left)
		{
			for (int i = left; i <= right; i++) //从左到右
				res.push_back(matrix[top][i]);

			for (int i = top + 1; i <= bottom; i++)//从右上到右下
				res.push_back(matrix[i][right]);

			if (top != bottom) //从右到左,若top=bottom,说明遍历完，若在从右往左则会重复遍历一遍。
				for (int i = right - 1; i >= left; i--)
					res.push_back(matrix[bottom][i]);

			if (left != right)//从下到上，若left=right,说明遍历完，若在从上到下则会重复遍历一遍。
				for (int i = bottom - 1; i>top; i--)
					res.push_back(matrix[i][left]);

			top++; left++; bottom--; right--;
		}

		return res;

	}
};

int main()
{
	/*vector<vector<int>> arr(3, vector<int>(4)); arr = { { 1,2,3,4}, {5,6,7,8}, { 9,10,11,12,},{ 13,14,15,16 } };
	vector<int> res;
	Solution b;*/
	

	int m, n, temp;
	cin >> "请输入矩阵的行和列:";
	cin >> m >> n;
	vector< vector<int> > arr(m, vector<int>(n));
	for (int i = 0; i<arr.size(); i++)
		for (int j = 0; j<arr[0].size(); j++)
		{
			cin >> temp;
			arr[i][j] = temp;
		}
	vector<int> res;
	Solution b;
	res = b.printMatrix(arr);
	for (int i = 0; i < res.size(); i++)
		cout << res[i] << " ";
	cout << endl;

	system("pause");
	return 0;

	
		
}