Slog 9

In this week’s lecture, we did several proves about the O(n^2) and Ω(n^2). First we did the prove about 3n^2 + 2n ∈ O(n^2). It was easy after seeing the answer; however the second question was really hard that I did not get it until I read the answer for several times. The second question is 7n^6 -5n^4 +2n^3∈ O(6n^8-4n^5+n^2). We need to make both (7n^6 -5n^4 +2n^3) and (6n^8-4n^5+n^2) as big as possible. So the value of c should be 4.5.The next type of question about disprove. The example is n^3∉O(3n^2). 

The next part of the lecture is about non-polynomials. We can use the limit function to solve non-polynomials. It totally confused. I hope I could do better in the next lecture.

Slog week8

The assignment 2 is difficult, and my group are confused about 1.2 and 1.3. I was really disappointed. In the beginning of the lecture the prof told us that there going to a term-exam on next Tuesday, and I was more disappointed. However, the prof gave us some hint about the assignment 2, and I felt a little bit confident about solving 1.2 and 1.3.

In this week’s lecture, I learnt about recap: O and Ω. O is the curve below the cn^2 after the break point; Ω is the curve above the cn^2 after the break point. The next part of the lecture is about algorithm.The algorithm is about the programming and the running time. The prof showed us some examples about the algorithm of the inserting sort.