螺旋输出N*N矩阵

 1 #include <iostream>
 2 #include <vector>
 3 using namespace std;
 4 int main() {
 5     int x[] = { 0, 1, 0, -1 };
 6     int y[] = { 1, 0, -1, 0 };
 7     int n;
 8     int pos_x = 0;
 9     int pos_y = 0;
10     cin >> n;
11     int counter = 1;
12     vector<vector<int> > A(n, vector<int>(n, 0));
13     int i;
14     for (i = n - 1; i > 0; i -= 2) {
15         for (int k = 0; k < 4; k++) {
16             for (int j = 0; j < i; j++) {
17                 A[pos_x][pos_y] = counter;
18                 counter++;
19                 pos_x += x[k];
20                 pos_y += y[k];
21             }
22         }
23         pos_x++;
24         pos_y++;
25     }
26     if (i == 0)
27         A[pos_x][pos_y] = counter;
28     for (int i = 0; i < n; i++) {
29         for (int j = 0; j < n; j++) {
30             cout << A[i][j] << "  ";
31         }
32         cout << endl;
33     }
34     return 0;
35 }