题解 | #顺时针打印矩阵#

1. 注意注释的细节

class Solution {
public:
    vector<int> printMatrix(vector<vector<int> > matrix) {
        if(!matrix.size()) return {};

        int top = 0, bottom = matrix.size()-1;
        int left = 0, right = matrix[0].size()-1;

        vector<int> res;


        while(top< (matrix.size()+1)/2&& left< (matrix[0].size()+1)/2){//向上取整小于中点

            //top

            for(int i = left; i<= right; i++){
                res.emplace_back(matrix[top][i]);
            }


            //right


            for(int i= top +1; i<=bottom;i++){//注意索引top + 1
                 res.emplace_back(matrix[i][right]);
            }


            //bottom

            for(int i = right-1; i>= left&&bottom!=top; i--){//除了注意索引，上下不能碰
                res.emplace_back(matrix[bottom][i]);
            }


            //left
            for(int i = bottom-1; i>= top+1&&left!=right; i--){//除了注意索引，左右不能碰
                res.emplace_back(matrix[i][left]);
            }

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

        }

        return res;

    }
};