这个代码比较简洁,但是不容易懂。
class Solution {
public:
vector<int> printMatrix(vector<vector<int> > matrix) {
vector<int> res;
int n = matrix.size();
if(!n) return res;
int m = matrix[0].size();
vector<vector<bool> > vis(n, vector<bool>(m, false));
int dx[4] ={-1,0,1,0}, dy[4]={0,1,0,-1};
int x = 0, y = 0, d = 1;
for(int i = 0; i < m*n ; i++){
res.push_back(matrix[x][y]);
vis[x][y] = true;
int a = x + dx[d], b = y + dy[d];
if(a < 0 || a >= n || b < 0 || b >= m || vis[a][b]){
d = (d + 1) % 4; //换个方向继续走
a = x + dx[d], b = y + dy[d];
}
x = a, y = b;
}
return res;
}
};