题解 | #螺旋矩阵#

class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param matrix int整型vector<vector<>> 
     * @return int整型vector
     */
    vector<int> spiralOrder(vector<vector<int> >& matrix) {
        // write code here
        std::vector<int> res;
        if (matrix.size() == 0) {
            return res;
        }
        int left = 0;
        int right = matrix[0].size() - 1;
        int up = 0;
        int down = matrix.size() - 1;

        while (true) {
            // 向右
            if (left > right) {
                break;
            }
            for (int i = left; i <= right; i++) {
                res.push_back(matrix[left][i]);
            }
            up++;
            // 向下
            if (up > down) {
                break;
            }
            for (int i = up; i <= down; i++) {
                res.push_back(matrix[i][right]);
            }
            right--;
            // 向左
            if (left > right) {
                break;
            }
            for (int i = right; i >= left; i--) {
                res.push_back(matrix[down][i]);
            }
            down--;
            // 向上
            if (up > down) {
                break;
            }
            for (int i = down; i >= up; i--) {
                res.push_back(matrix[i][left]);
            }
            left++;
        }

        return res;
    }
};