The common link of friendship between the two friends was snapped when he went to the university.

Explanation:

When the friend went to the university, he was exposed to a new environment and a new set of people. This led to a change in his personality and interests, which might have caused a drift in the friendship. The following reasons could have contributed to the snapping of their friendship:

1. Different schedules: When one friend goes to university, their schedules become very different from each other. The university schedule is more rigorous and demanding, and the friend may not have enough time to spend with their old friend.

2. Distance: Going to university often means moving away from home, which means that the friends might be living far apart from each other. This distance can make it difficult to maintain the friendship.

3. New friends: Going to university means meeting new people, and the friend might have made new friends who shared his interests and hobbies. This could have led to a shift in his priorities, and he might have spent more time with his new friends than his old friend.

4. Different interests: University exposes students to a variety of new subjects and areas of interest. The friend might have found new interests that his old friend did not share. This could have made it difficult for them to connect and maintain their friendship.

In conclusion, the common link of friendship was snapped when the friend went to the university due to different schedules, distance, new friends, and different interests.

Because going to University, author and grandmother use to share their room, that was the common like between them, now author was given a separate room to study.