poj Selecting Courses

把课程和对应的课来做最大二分匹配，一天有12节课，map[c][(p-1)*12+q]即把课程与对应的课存进去了，然后就是最大二分匹配了

#include<iostream>#include<algorithm>#include<string.h>#include<stack>#include<queue>#include<math.h>#include<cstdio>using namespace std;int map[310][310];int match[310];bool vis[310];int n,m;bool dfs(int u){for(int i=1;i<=m;i++){if(!vis[i] && map[u][i]){vis[i]=1;if(match[i]==-1 || dfs(match[i])){match[i]=u;return true;}}}return false;}int Match(){int sum=0;for(int i=0;i<n;i++){memset(vis,0,sizeof(vis));if(dfs(i))sum++;}return sum;}int main(){int c,p,q;while(~scanf("%d",&n)){memset(map,0,sizeof(map));memset(match,-1,sizeof(match));m=12*7;for(int i=0;i<n;i++){scanf("%d",&c);while(c--){scanf("%d%d",&p,&q);map[i][(p-1)*12+q]=1;}}printf("%d\n",Match());}return 0;}