13 星期四 11月 2014
This week we learned more about proof for big O and big Omega, and then we also learned big Theta. When we do the proof, there is B and c in it, I found a little bit hard to understand the relationship of those two in the proof, also in the definition.
07 星期五 11月 2014
This week we had term test 2, after doing assignment 2 I felt more confident with the term test 2, and I did past test as well. Moreover, we learned more about big O, big omega and counting steps. Counting steps is like run the whole thing in your mind and get the idea of what’s going on each line. It sometimes confuse me a lot because of the ‘n’s and add/minus with the previous line or something like that.
31 星期五 10月 2014
This week we learned about O, Ω. O(n2) is set of functions that grow no faster than n2; Ω(n2) is set of functions that grow no slower than n2. It is also in worst case analyses, that we need to determine which algorithm is in the case and then find the solution. The definition of those two is kinda confusing at first and also while in the problem.
24 星期五 10月 2014
This week we cleared different inference that we could use in proof, and then we learned about sorting. There are different ways of sorting, such as inserting sort and selection sort. Inserting sort is like check every card one by one and change positions while you check. Selection sort is like you know what you are looking for and then you scan the whole thing and get what you want then sort it to the position. But inserting sort and selection sort take more steps if you have lots of cards. So we want a way that can deal with the problem more quickly.
16 星期四 10月 2014
Last week we learned the structure of proof, and this week we learned more about proof. For example, by using contrapositive to prove if the implication, since the contrapositive of the original implication is the same as the original one. Using contrapositive makes proof easier sometimes. Proof is difficult to solve so we need to use different ways to help us make it easier to deal with.
10 星期五 10月 2014
This week we learned proof and also had the midterm. I didn’t finish the last question because at that time I couldn’t find examples. Proof seems hard, but the structure is kinda easy to do. Sometimes it’s hard to make a proof of something we already known well and seems basic to us, such as n is odd, then (n+1)square is also odd.
03 星期五 10月 2014
This week we learned bi-implication, negation of bi-implication, transitivity, mixed quantifiers, and find/write proof.
I found that bi-implication and the negation of bi-implication is hard to translate between the mathematical symbols and english words. Especially in the assignment 1, it’s difficult to first understand the english meaning, translate it to symbolic, then negate it. Usually we need a venn diagram or truth table to help us dealing the logical problem to prove if we make it right or wrong.
27 星期六 9月 2014
This week we learned about conjunction, disjunction, negation and implication. While conjunction is like “and”, disjunction is like “or”, negation means not, and it is kinda similar to “-” in math. When these are used in a implication, we can use a Venn diagram(usually using circles) or make a truth table(comparing True/False). I found when putting negation with conjunction and disjunction together, the problem gets confusing and always take longer time to solve. While in the tutorial, a lot of those kind of questions comes up and I’m feeling lost. It takes time to absorb the points Danny taught and in the slides, and also I think I need to practice more to get used to this kind of way of thinking problems.
19 星期五 9月 2014
The 2nd week I find implication is interesting, that I have to think about it with a lot of concerns. Sometimes the meaning of a implication is different with the meaning we say it in life. Implication is interesting not just because of its different meanings also because it can be conversed and contrapositive, which make statements with more fun and more difficulty when you think about them, and I find it is quite challenge.
yzslog2014 