73 lines
2.0 KiB
Markdown
73 lines
2.0 KiB
Markdown
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# Binary Search Tree
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Write a program that inserts numbers and searches in a binary tree.
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When we need to represent sorted data, an array does not make a good
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data structure.
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Say we have the array `[1, 3, 4, 5]`, and we add 2 to it so it becomes
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`[1, 3, 4, 5, 2]` now we must sort the entire array again! We can
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improve on this by realizing that we only need to make space for the new
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item `[1, nil, 3, 4, 5]`, and then adding the item in the space we
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added. But this still requires us to shift many elements down by one.
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Binary Search Trees, however, can operate on sorted data much more
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efficiently.
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A binary search tree consists of a series of connected nodes. Each node
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contains a piece of data (e.g. the number 3), a variable named `left`,
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and a variable named `right`. The `left` and `right` variables point at
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`nil`, or other nodes. Since these other nodes in turn have other nodes
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beneath them, we say that the left and right variables are pointing at
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subtrees. All data in the left subtree is less than or equal to the
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current node's data, and all data in the right subtree is greater than
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the current node's data.
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For example, if we had a node containing the data 4, and we added the
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data 2, our tree would look like this:
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4
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/
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2
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If we then added 6, it would look like this:
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4
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/ \
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2 6
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If we then added 3, it would look like this
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4
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/ \
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2 6
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\
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3
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And if we then added 1, 5, and 7, it would look like this
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4
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/ \
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/ \
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2 6
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/ \ / \
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1 3 5 7
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To run the tests simply run the command `go test` in the exercise directory.
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If the test suite contains benchmarks, you can run these with the `-bench`
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flag:
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go test -bench .
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For more detailed info about the Go track see the [help
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page](http://exercism.io/languages/go).
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## Source
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Josh Cheek [https://twitter.com/josh_cheek](https://twitter.com/josh_cheek)
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## Submitting Incomplete Problems
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It's possible to submit an incomplete solution so you can see how others have completed the exercise.
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