剑指 Offer 29. 顺时针打印矩阵

class Solution {
public:
    vector spiralOrder(vector>& matrix) {
        vector res;
        if(matrix.empty()) return res;

        int t=0,d=matrix.size()-1;
        int l=0,r=matrix[0].size()-1;

        while(1){
            for(int i=l;i<=r;i++){
                res.push_back(matrix[t][i]);
            } 
            if(++t>d) break;
            for(int i=t;i<=d;i++){
                res.push_back(matrix[i][r]);
            } 
            if(--r=l;i--){
                res.push_back(matrix[d][i]);
            } 
            if(--d=t;i--) {
                res.push_back(matrix[i][l]);
            }
            if(++l>r) break;
        }
        return res;

    }
};