20162314 2017-2018-1 《Program Design & Data Structures》Learning Summary Of The Eighth Week
Summary of Key Concepts
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A binary search tree is a binary tree in which, for each node, the elements in the left subtree are less than the parent, and the elements in the right subtree are greater than or equal to the parent.
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The most efficient binary search trees are balanced, so that half of the viable candidates are eliminated with each comparison.
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Without any additional processing, the shape of a binary search tree is dictated by the order in which elements are added to it.
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There are three situations to consider when removing an element from a binary search tree, two of which are straightforward.
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When removing a node with two children from a binary search tree, the inorder successor is a good choice to replace it.
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Rotations can be performed on a binary search tree to help rebalance them.
Problem and solution in teaching materials.
Why is it important for a binary search tree to be balanced(or close to balanced)?
- If a binary search tree is balanced, approximately half of the elements are eliminated from consideration with each comparison.
- The more unbalanced the tree, the closer it gets to a linear structure, which is much less efficient.
What is the most interesting situation when removing an element from a binary search tree?
- The most interesting situation when removing an element from a binary search tree occurs when the element has two children,
- because there is no simple option to replace the element (as there are if it has one child or no children).
What is a binary search tree rotation?
- A binary search tree rotation is an operation that helps put a binary search tree back into a balanced state.
Code hosting
Summary of error for last week.
Linear search is always more effective than binary search.The answer should be false, for the situation of "n = 2".
Evaluate for my partner
- Advantage and problem in the blog：
- Concise and comprehensie
- Uncleary to the content
- Mould is amazing
- Advantage and problem in the code：
- Serious writing.
- Wonderful idea
- Too less
Learning situation of partner
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Learning content of partner：
- Algorithm
- Recursion
- HanoiTowers and maze
Anything else that want to say
- It's not easy to persere on utizing English to write a blog.But I'm getting used to doing this because of the benefit.
Academic progress check
| Code line number（increasing/accumulative） | Blog number（inc/acc） | studying time（inc/acc） | progress | |
|---|---|---|---|---|
| target | 5000lines | 30articles | 400hours | |
| First week | 180/180 | 1/1 | 20/20 | |
| Second week | 1049/1229 | 1/2 | 18/38 | |
| Third week | 1037/2266 | 3/7 | 22/60 | |
| Fourth week | 1120/3386 | 2/9 | 30/90 |