顺时针打印矩阵

 1 vector<int> spiralOrder(vector<vector<int>>& matrix) {
 2 vector<int> arr;
 3 if(matrix.empty())        
 4   return arr;
 5 int len = matrix.size();
 6 int wid = matrix[0].size();
 7 vector<int> vis(len*wid,0);
 8 int i = 0,j = 0;
 9 bool sign = true;
10 
11 while(sign) {
12   if(i < len && j < wid){
13       if(vis[i*len+j]==0)  {arr.push_back(matrix[i][j]); vis[i*len+j] = 1;}
14       if(j+1<wid) { if(vis[i*len+j]==0)  { j++; continue; }}
15       if(i+1 <len) { if(vis[i*len+j]==0) { i++; continue; }}
16       if(j > 0) { if(vis[i*len+j]==0){ j--; continue;}}
17       if(i > 0) { if(vis[i*len+j]==0}{ while(vis[(i-1)*len+j]==0) { i--;
18                       arr.push_back(matrix[i][j]);  vis[i*len+j] = 1; } }
19       if(arr.size() == len*wid) sign = false;
20 }
21       return arr;
22 }
23 }