poj1469 COURSES

#include<iostream>#include<cstring>#include<cstdio>using namespace std;bool a[105][305];bool used[305];int mat[305];int p,n;bool crosspath(int k){int i;for(i=1;i<=n;i++)if(a[k][i]==1&&used[i]==0){used[i]=1;if(mat[i]==0||crosspath(mat[i])){mat[i]=k;return 1;}}return 0;}int main(){int t;int i,j;int pi,stu;scanf("%d",&t);while(t--){memset(a,0,sizeof(a));memset(mat,0,sizeof(mat));scanf("%d%d",&p,&n);for(i=1;i<=p;i++){scanf("%d",&pi);for(j=1;j<=pi;j++){scanf("%d",&stu);a[i][stu]=1;}}int match=0;for(i=1;i<=p;i++){memset(used,0,sizeof(used));if(crosspath(i))match++;}if(match==p)printf("YES\n");elseprintf("NO\n");}return 0;}