螺旋矩阵

class Solution {
public:
    vector<int> spiralOrder(vector<vector<int>>& matrix) {
        //if()
         vector<int> result;
        if(matrix.empty())  return result;
        int i1 = 0;
        int i2 = matrix.size()-1;
        int j1 = 0;
        int j2 = matrix[0].size()-1;
        while(true){
            //从左到右
            for(int n = j1; n<=j2; n++){
                result.push_back(matrix[i1][n]);
            }
            //if(result.size() == matrix.size()*matrix[0].size()) break;
            if(++i1 > i2 ) break;
            //从上到下
            for(int i = i1;i<=i2;i++){
                result.push_back(matrix[i][j2]);
            }
            //if(result.size() == matrix.size()*matrix[0].size()) break;
            //j2--;
            if(--j2 < j1) break;
            //从右到左
            for(int j = j2;j>=j1;j--){
                result.push_back(matrix[i2][j]);
            }
            //if(result.size() == matrix.size()*matrix[0].size()) break;
            if(--i2 <i1) break;
            //从下到上
            for(int k = i2; k >= i1;  k--){
                result.push_back(matrix[k][j1]);
            }
            //if(result.size() == matrix.size()*matrix[0].size()) break;
            if(++j1 > j2) break;
            //j1++;            
            
        }
        
        for(int i = 0; i < result.size(); i++){ 
            cout << result[i] << ",";
        }
        return result;
    }
};