題目地址:1034. Forest
思路:
待續.......
具體代碼如下:
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 }