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http://poj.org/problem?id=1469
匈牙利算法
邻接矩阵版
1 #include <iostream> 2 #include <cstdio> 3 #include <vector> 4 using namespace std; 5 6 const int maxNodes = 405; 7 8 int G[110][310]; 9 10 int num_left; 11 int num_right; 12 13 int checked[310]; 14 int matching[310]; 15 16 bool dfs(int u) 17 { 18 for(int v = 0; v < num_right; v++) 19 { 20 if(G[u][v] == 1 && !checked[v]) 21 { 22 checked[v] = true; 23 if(matching[v] == -1 || dfs(matching[v])) 24 { 25 matching[v] = u; 26 return true; 27 } 28 } 29 } 30 return false; 31 } 32 33 int hungarian() 34 { 35 memset(matching, -1, sizeof(matching)); 36 int ans = 0; 37 38 for(int u = 0; u < num_left; u++) 39 { 40 memset(checked, 0, sizeof(checked)); 41 if(dfs(u)) 42 { 43 ans++; 44 } 45 } 46 return ans; 47 } 48 49 int main() 50 { 51 int n; 52 scanf_s("%d", &n); 53 while(n--) 54 { 55 memset(G, 0, sizeof(G)); 56 57 scanf_s("%d%d", &num_left, &num_right); 58 bool flag = true; 59 for(int u = 0; u < num_left; u++) 60 { 61 int t; 62 scanf_s("%d", &t); 63 if(t == 0) 64 { 65 flag = false; 66 } 67 for(int j = 0; j < t; j++) 68 { 69 int v; 70 scanf_s("%d", &v); 71 G[u][v-1] = 1; 72 } 73 } 74 75 if(!flag) 76 { 77 cout<<"NO"<<endl; 78 } 79 else 80 { 81 int res = hungarian(); 82 if(num_left == res) 83 { 84 cout<<"YES"<<endl; 85 } 86 else 87 { 88 cout<<"NO"<<endl; 89 } 90 } 91 } 92 }
邻接表版
1 #include <iostream> 2 #include <vector> 3 #include <cstdio> 4 using namespace std; 5 6 const int maxNodes = 405; 7 8 struct Edge 9 { 10 int from; 11 int to; 12 int weight; 13 14 Edge(int f, int t, int w):from(f), to(t), weight(w){} 15 }; 16 17 vector<int> G[maxNodes]; 18 vector<Edge> edges; 19 20 int num_nodes; 21 int num_left; 22 int num_right; 23 int num_edges; 24 25 int checked[maxNodes]; 26 int matching[maxNodes]; 27 28 bool dfs(int u) 29 { 30 vector<int>::iterator it; 31 for(it = G[u].begin(); it != G[u].end(); it++) 32 { 33 int v = *it; 34 if(!checked[v]) 35 { 36 checked[v] = true; 37 if(matching[v] == -1 || dfs(matching[v])) 38 { 39 matching[v] = u; 40 return true; 41 } 42 } 43 } 44 return false; 45 } 46 47 int hungarian() 48 { 49 memset(matching, -1, sizeof(matching)); 50 int ans = 0; 51 52 for(int u = 0; u < num_left; u++) 53 { 54 memset(checked, 0, sizeof(checked)); 55 if(dfs(u)) 56 { 57 ans++; 58 } 59 } 60 return ans; 61 } 62 63 int main() 64 { 65 int n; 66 scanf_s("%d", &n); 67 while(n--) 68 { 69 edges.clear(); 70 for(int i = 0; i < maxNodes; i++) 71 { 72 G[i].clear(); 73 } 74 bool flag = true; 75 scanf_s("%d%d", &num_left, &num_right); 76 for(int u = 0; u < num_left; u++) 77 { 78 int t; 79 scanf_s("%d", &t); 80 if(t == 0) 81 { 82 flag = false; 83 } 84 for(int j = 0; j < t; j++) 85 { 86 int v; 87 scanf_s("%d", &v); 88 edges.push_back(Edge(u, v-1, 1)); 89 G[u].push_back(v-1); 90 } 91 } 92 93 if(flag) 94 { 95 if(num_left == hungarian()) 96 { 97 cout<<"YES"<<endl; 98 } 99 else 100 { 101 cout<<"NO"<<endl; 102 } 103 } 104 else 105 { 106 cout<<"NO"<<endl; 107 } 108 } 109 }
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原文地址：http://www.cnblogs.com/ygw0616/p/4504522.html
