顺时针打印矩阵

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.

没什么水平的题，不能通过的原因可能是不太细心
思路：记录矩形四个角的坐标
（x, y） (x, col-x-1)

(row-x-1, y) (row-x-1, col-x-1)

每次循环递增x和y就OK

code:

class Solution {public:    vector<int> printMatrix(vector<vector<int> > matrix)     {        vector<int> answer;        int row= matrix.size();        if(0 == row)        {            return answer;        }        int col= matrix[0].size();        if(0 == col)        {            return answer;        }        int totalNumber= row* col;        int x= 0,y= 0;        int cutIdx= 0;        while(true)        {            for(int i= y; i<= col-x-1; ++i)            {                answer.push_back(matrix[x][i]);                if(totalNumber == answer.size())                {                    return answer;                }            }            for(int i= x+1; i<= row-x-1; ++i)            {                answer.push_back(matrix[i][col-1-x]);                if(totalNumber == answer.size())                {                    return answer;                }            }            for(int i= col-x-2; i>= y; --i)            {                answer.push_back(matrix[row-x-1][i]);                if(totalNumber == answer.size())                {                    return answer;                }            }            for(int i= row-x-2; i>= x+1; --i)            {                answer.push_back(matrix[i][y]);                if(totalNumber == answer.size())                {                    return answer;                }            }            ++x;            ++y;        }        return answer;    }};