mystical_curve的博客

B - The Accomodation of Students There are a group of students. Some of them may know each other, while others don’t. For example, A and B know each other, B and C know each other. But this may not i

C - Courses Consider a group of N students and P courses. Each student visits zero, one or more than one courses. Your task is to determine whether it is possible to form a committee of exactly P stude