1 class Solution {
2 public:
3 vector<int> spiralOrder(vector<vector<int> > &matrix) {
4 // Note: The Solution object is instantiated only once and is reused by each test case.
5 vector<int> rlt;
6 int m =matrix.size();
7 if (m<=0)
8 return rlt;
9 int n = matrix[0].size();
10 if (n<=0)
11 return rlt;
12 int flag[4] = {0, m-1, 0, n-1};
13 int direction = 0; //left 2 right;
14 int i = 0;
15 while (true){
16 int j = 2 - 2 * (direction%2); //j=0 or j=2
17 if (flag[j]>flag[j+1])
18 break;
19 int start = flag[j]*(1-direction/2) + flag[j+1]*(direction/2); // start of iteration
20 int delta = 1 - direction/2 - direction/2;
21 for (i=start; i<=flag[j+1] && i>=flag[j]; i+=delta){
22 int rowIndex = i*(direction%2)+ flag[0]*(((direction+3)%4)/3) + flag[1]*(((direction+1)%4)/3);
23 int colIndex = i*(1-direction%2)+flag[3]*(((direction+2)%4)/3) + flag[2]*(direction/3);
24 rlt.push_back(matrix[rowIndex][colIndex]);
25 }
26 int index = 2*(direction%2) + ((direction+1)%4)/2;
27 flag[index] = flag[index] - ((direction+1)%4)/2 + ((direction+3)%4)/2;
28 direction = (direction+1)%4;
29 }
30 return rlt;
31 }
32 };
1 class Solution {
2 public:
3 vector<int> spiralOrder(vector<vector<int> > &matrix) {
4 // Note: The Solution object is instantiated only once and is reused by each test case.
5 vector<int> rlt;
6 int m =matrix.size();
7 if (m<=0)
8 return rlt;
9 int n = matrix[0].size();
10 if (n<=0)
11 return rlt;
12 int flag[4] = {0, m-1, 0, n-1};
13 int direction = 0; //left 2 right;
14 int i = 0;
15 while (true){
16 int j = 2 - 2 * (direction%2); //j=0 or j=2
17 if (flag[j]>flag[j+1])
18 break;
19 int start = flag[j]*(1-direction/2) + flag[j+1]*(direction/2); // start of iteration
20 int delta = 1 - direction/2 - direction/2;
21 for (i=start; i<=flag[j+1] && i>=flag[j]; i+=delta){
22 int rowIndex = i*(direction%2)+ flag[0]*(((direction+3)%4)/3) + flag[1]*(((direction+1)%4)/3);
23 int colIndex = i*(1-direction%2)+flag[3]*(((direction+2)%4)/3) + flag[2]*(direction/3);
24 rlt.push_back(matrix[rowIndex][colIndex]);
25 }
26 int index = 2*(direction%2) + ((direction+1)%4)/2;
27 flag[index] = flag[index] - ((direction+1)%4)/2 + ((direction+3)%4)/2;
28 direction = (direction+1)%4;
29 }
30 return rlt;
31 }
32 };
