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 45 6 7 89 10 11 1213 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.

class Solution {

public:

    vector<int> printMatrix(vector<vector<int> > matrix) {

              vector<int>  ans;

              introw=matrix.size();

              intcol=matrix[0].size();

            if(row==0|| col==0)  return  ans;

            inttop=0,left=0,right=col-1,bottom=row-1;

            while(left<=right && top<=bottom)

           {

                for(intj=left;j<=right;++j)

                     ans.push_back(matrix[top][j]);

                for(inti=top+1;i<=bottom;++i)

                     ans.push_back(matrix[i][right]);

                if(top!=bottom)

                for(intj=right-1;j>=left;--j)

                     ans.push_back(matrix[bottom][j]);

                if(left!=right)

                for(inti=bottom-1;i>top;--i)

                     ans.push_back(matrix[i][left]);

                left++,right--,top++,bottom--;

           }

            returnans;

    }

};