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，例如，如果输入如下矩阵： 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 则依次打印出数字1,2,3,4,8,12,16,15,14,13,9,5,6,7,11,10.

// test14.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include<iostream>
#include<string>
#include<cctype>
#include <vector>
#include<exception>
#include <initializer_list>
#include<stack>
using namespace std;

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

		int row1 = 0, row2 = matrix.size();
		int col1 = 0, col2 = matrix[0].size();
		vector<int> result;
		
		while (true)
		{
			//从左到右打印
			for (int i = col1; i < col2; i++)
			{
				result.push_back(matrix[row1][i]);
		
			}
			row1++; 
			if (row1 >= row2)break; //循环终止条件
			
			//从上往下打印
			for (int i = row1; i < row2; i++)
			{
				result.push_back(matrix[i][col2-1]);
		
			}
			col2--; 
			if (col1 >= col2)break;

			//从右往左打印
			for (int i = col2-1; i >= col1; i--)
			{
				result.push_back(matrix[row2-1][i]);
			
			}
			row2--; 
			if (row1 >= row2)break;

			//从下往上打印
			for (int i = row2-1; i >= row1; i--)
			{
				result.push_back(matrix[i][col1]);
			}
			col1++;
			if (col1 >= col2)break;
	
		}
		
		return result;
	}
};

int main()
{
	
	Solution so;
	vector<vector<int>> matrix;
	vector<int> vec;
	vector<int> result;

	vec = { 1,2,3,4};
	matrix.push_back(vec);
	vec = { 5,6,7,8 };
	matrix.push_back(vec);
	vec = { 9,10,11,12 };
	matrix.push_back(vec);
	vec = {13,14,15,16 };
	matrix.push_back(vec);
	
	result = so.printMatrix(matrix);

	while (!result.empty())
	{
		cout << *(result.end()-1) << "  ";
		result.pop_back();
	}
 

	cout << endl;
	return 0;
}