Poj--2239（二分图最大匹配）
2014-11-04 17:41:40
思路：以课程编号为X集合，时间为Y集合，进行匹配即可。比较裸的匈牙利。
1 /************************************************************************* 2 > File Name: 2239.cpp 3 > Author: Nature 4 > Mail: 564374850@qq.com 5 > Created Time: Sun 02 Nov 2014 05:36:32 PM CST 6 ************************************************************************/ 7 8 #include <cstdio> 9 #include <cstring> 10 #include <cstdlib> 11 #include <cmath> 12 #include <vector> 13 #include <map> 14 #include <set> 15 #include <stack> 16 #include <queue> 17 #include <iostream> 18 #include <algorithm> 19 using namespace std; 20 #define lp (p << 1) 21 #define rp (p << 1|1) 22 #define getmid(l,r) (l + (r - l) / 2) 23 #define MP(a,b) make_pair(a,b) 24 typedef long long ll; 25 const int INF = 1 << 30; 26 const int maxn = 310; 27 28 int n; 29 int first[maxn],next[maxn * 100],ver[maxn * 100],ecnt; 30 int used[maxn],mat[maxn]; 31 32 void Init(){ 33 memset(first,-1,sizeof(first)); 34 ecnt = 0; 35 } 36 37 void Add_edge(int u,int v){ 38 next[++ecnt] = first[u]; 39 ver[ecnt] = v; 40 first[u] = ecnt; 41 } 42 43 bool find(int p){ 44 for(int i = first[p]; i != -1; i = next[i]){ 45 int v = ver[i]; 46 if(used[v] == 0){ 47 used[v] = 1; 48 if(mat[v] == 0 || find(mat[v])){ 49 mat[v] = p; 50 return true; 51 } 52 } 53 } 54 return false; 55 } 56 57 int Hungary(){ 58 int ans = 0; 59 memset(mat,0,sizeof(mat)); 60 for(int i = 1; i <= n; ++i){ 61 memset(used,0,sizeof(used)); 62 if(find(i)) ++ans; 63 } 64 return ans; 65 } 66 67 int main(){ 68 int a,b,c; 69 while(scanf("%d",&n) != EOF){ 70 Init(); 71 for(int i = 1; i <= n; ++i){ 72 scanf("%d",&a); 73 while(a--){ 74 scanf("%d%d",&b,&c); 75 Add_edge(i,(b - 1) * 12 + c); 76 } 77 } 78 printf("%d\n",Hungary()); 79 } 80 return 0; 81 }
