Sicily 1034. Forest

题目地址：1034. Forest

思路：

     网上很多说用深搜，很任性.......发现广搜也挺好用的，实验课打的(⊙o⊙)…orz........囧。

     先找根结点，根据根结点广搜深度，广搜宽度，不过要开一个数组，同一层的累加宽度。别忘了要判断是否合法。

     具体代码如下：

 1 #include <iostream>

 2 #include <cstring>

 3 #include <queue>

 4 using namespace std;

 5 

 6 bool path[101][101];

 7 bool visited[101];

 8 bool Root[101];

 9 

10 int main()

11 {

12     int n, m;

13     while (cin >> n >> m && n)

14     {

15         memset(path, false, sizeof(path));

16         memset(visited, false, sizeof(visited));

17         memset(Root, true, sizeof(Root));

18 

19         bool flag = n > m ? true : false;

20         for (int i = 1; i <= m; i++)

21         {

22             int node1, node2;

23             cin >> node1 >> node2;

24             if (node1 == node2) flag = false;

25             path[node1][node2] = true;

26         }

27         if (flag == false) {

28             cout << "INVALID\n";

29             continue;

30         }

31         

32         for (int i = 1; i <= n; i++)

33             for (int j = 1; j <= n; j++)

34                 if (path[j][i])

35                     Root[i] = false;

36         int maxwidth = 0;

37         for (int i = 1; i <= n; i++)

38             if (Root[i]) {

39                 maxwidth++;

40                 visited[i] = true;

41             }

42         queue<int> store;

43         int depth, maxdepth;

44         maxdepth = depth = 0;

45         int width[101] = {0};

46         for (int i = 1; i <= n; i++)

47         {

48             if (Root[i])

49             {

50                 store.push(i);

51                 depth = 0;

52                 while (!store.empty())

53                 {

54                     int size = store.size();

55                     width[depth] += size;

56                     while (size--)

57                     {

58                         for (int j = 1; j <= n; j++)

59                             if (path[store.front()][j])

60                             {

61                                 if (!visited[j]) {

62                                     store.push(j);

63                                     visited[j] = true;

64                                 }

65                                 else

66                                     flag = false;

67                             }

68                         store.pop();

69                     }

70                     if (!store.empty())

71                         depth++;

72                 }

73                 maxdepth = depth > maxdepth ? depth : maxdepth;

74             }

75         }

76         

77         for (int i = 1; i <= n; i++)

78             if (!visited[i]) {

79                 flag = false;

80                 break;

81             }

82         

83         for (int i = 0; i <= maxdepth; i++)

84             maxwidth = width[i] > maxwidth ? width[i] : maxwidth;

85         

86         flag == false ? cout << "INVALID" : cout << maxdepth << " " << maxwidth;

87         cout << endl;

88     }

89 

90     return 0;

91 }