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

class Solution {
public:
    vector<int> printMatrix(vector<vector<int> > matrix) {
        int total=0;
        int row_len = matrix.size();
        int line_len = matrix[0].size();
         
        int row_min = 0;
        int row_max = row_len-1;
        int line_min = 0;
        int line_max = line_len - 1;
        int i=0,j=0;
        vector< int > res;
  
        if(!matrix.empty() && row_len > 0 && line_len > 0)
        {
            while(total < row_len * line_len)
            {
                while(j >= line_min && j <= line_max)
                    {
                    res.push_back(matrix[i][j++]);
                    total++;
                }
                     
                j--;
                i++;
                row_min++;
                if(i<row_min || i>row_max)
                    break;
  
                while( i >= row_min && i <= row_max)
                    {
                    res.push_back(matrix[i++][j]) ;
                    total++;
                }
                   
                i--;
                j--;
                line_max--;
                if(j>line_max || j<line_min)
                    break;
  
                while( j >= line_min && j <= line_max)
                    {
                    res.push_back(matrix[i][j--]) ;
                    total++;
                }
                    
                j++;
                i--;
                row_max--;
                 if(i<row_min || i>row_max)
                    break;
  
                while( i>= row_min && i<= row_max)
                    {
                    res.push_back(matrix[i--][j]) ;
                    total++;
                }
                     
                i++;
                j++;
                line_min++;
                if(j>line_max || j<line_min)
                    break;
            }
        }
          
        return res;
    }
 
};