剑指offer 20：顺时针打印矩阵

class Solution {
public:
    vector<int> printMatrix(vector<vector<int> > matrix) {
        vector<int> result;
        int row=matrix.size();
        if(row==0){
            return result;
           }
        int col=matrix[0].size();
        if(col==0){
            return result;
        }
        int  start=0;
        while(start*2<row && col>start*2){
            printCycle(matrix,result,row,col,start);
            start++;
        }
        return result;
        
    }
    void printCycle(const vector<vector<int> > & ori, vector<int> & result,int row,int col, int start){
        int endrow=row-start-1;
        int endcol=col-start-1;
        
        for (int i=start;i<=endcol;i++){//从左向右打印一行
            result.push_back(ori[start][i]);
        }
        if(endrow>start){
            for (int i=start+1;i<=endrow;i++){//从上到下打印一列
            result.push_back(ori[i][endcol]);
            }
        }
        if(endcol>start && endrow>start){
            for (int i=endcol-1;i>=start;i--){//从右向左打印一行
            result.push_back(ori[endrow][i]);
            }
        }
        if(endcol>start && endrow>start+1){
            for (int i=endrow-1;i>start;i--){//从右向左打印一行
            result.push_back(ori[i][start]);
            }
        }

    }
};