一道關於C++二維數組的問題

10 9 8 7

[cpp]

1. #include <vector>
2. #include <iostream>
3. using namespace std;
5. int main()
6. {
7. int n;
8. int i, j;
9. int t;
10. int flag = 1;
11. vector< vector<int> > Matrix;
13. cout << "輸入n: \n";
14. cin >> n;
15. Matrix.resize(n);
16. for(i=0; i<n; i++)
17. Matrix[i].resize(n);
19. i = j = 0;
21. for(i=0; i<n; i++)
22. for(j=0; j<n; j++)
23. Matrix[i][j] = -1;
25. i = j = 0;
26. t = 1;
28. while(t <= n*n)
29. {
30. if(flag == 1)
31. {
32. if(Matrix[i][j] == -1)
33. {
34. Matrix[i][j] = t;
35. j++;
36. if(j+1 >= n || Matrix[i][j+1] != -1)
37. flag = 2;
38. }
39. }
40. else if(flag == 2)
41. {
42. if(Matrix[i][j] == -1)
43. {
44. Matrix[i][j] = t;
45. i++;
46. if(i+1 >= n || Matrix[i+1][j] != -1)
47. flag = 3;
48. }
49. }
50. else if(flag == 3)
51. {
52. if(Matrix[i][j] == -1)
53. {
54. Matrix[i][j] = t;
55. j--;
56. if(j-1 < 0 || Matrix[i][j-1] != -1)
57. flag = 4;
58. }
59. }
60. else if(flag == 4)
61. {
62. if(Matrix[i][j] == -1)
63. {
64. Matrix[i][j] = t;
65. i--;
66. if(i-1 < 0 || Matrix[i-1][j] != -1)
67. flag = 1;
68. }
69. }
70. ++t;
71. }
73. for(i=0; i<n; i++)
74. {
75. for(j=0; j<n; j++)
76. {
77. cout << Matrix[i][j];
78. if(j!=n-1)
79. cout << ' ';
80. else
81. cout << '\n';
82. }
83. }
84. return 0;
85. }