题解 | #牛牛的顺时针遍历#

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
        vector<int> res;
        int x = 0, y = 0;
        int L = matrix.size(), W = matrix[0].size();
        while (true) {
            res.push_back(matrix[x][y]);
            int step = W - 1;
            if(step == 0) break;
            // right
            while(step!=0){
                y++;
                step--;
                res.push_back(matrix[x][y]);
            }
            // down
            step = L-1;
            if(step == 0) break;
            while(step!=0){
                x++;
                step--;
                res.push_back(matrix[x][y]);
            } 
            // left           
            step = W - 1;
            while(step!=0){
                y--;
                step--;
                res.push_back(matrix[x][y]);
            }
             // up        
            step = L - 2;
            if(step == 0) break;
            while(step!=0){
                x--;
                step--;
                res.push_back(matrix[x][y]);
            } 

            y++;
            W-=2;
            L-=2;  
            if(W==0 || L==0) break;    
        }
        return res;
    }
};