Article: Hash Tables and Hash Functions #1047
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| ## Introduction to hashing | ||
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| Hashing is designed to solve the problem of needing to efficiently find or store an item in a collection. |
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Maybe link to some good external article on what hashing is?
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I meant to say link to some Wikipedia article that defines Hashing. where you first use the word Hashing.
| keys = my_hash_table.keys() | ||
| values = my_hash_table.values() | ||
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In the implementation part, you can make it absolutely clear that some of these languages come with in-built Hashing support. Like, when you are using Java Hashmap, do mention |
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@alayek I've implemented your suggestions. I've added links to interesting videos on hashing, if that's alright. |
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Yes, add as many good resources you can add. In fact, add a separate section on resources altogether! |
Hash-Tables-and-Hashing Functions.md
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| ## Interesting Links | ||
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| - If what I've said doesn't make any sense to you, you may want to check out [this video](https://www.youtube.com/watch?v=x05KubVlh_M). |
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If what I've said doesn't make any sense to you
I understand you are striking a humorous tone, but better just say it plainly
For further reading
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@atjonathan @abhisekp @koustuvsinha please check. |
Hash-Tables-and-Hashing Functions.md
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| Now, in this specific example things work quite well. | ||
| Our array needs to be big enough to accommodate the longest string, but in this case that’s only 11 slots. | ||
| And we do waste a bit of space because, for example, there are no 1-letter keys in our data, nor keys between 8 and 10 letters. But in this case, the waste isn’t so bad either. And taking the length of a string is nice and fast, so is the process of finding the value associated with a given key (certainly faster than doing up to five string comparisons). |
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the waste the wasted space
And taking Taking
so is and so is
| And we do waste a bit of space because, for example, there are no 1-letter keys in our data, nor keys between 8 and 10 letters. But in this case, the waste isn’t so bad either. And taking the length of a string is nice and fast, so is the process of finding the value associated with a given key (certainly faster than doing up to five string comparisons). | ||
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| But, what do we do if our dataset has a string which has more than 11 characters? | ||
| What if we have one another word with 5 characters, "India", and try assigning it to an index using our hash function. Since the index 5 is already occupied, we have to make a call on what to do with it. This is called a collision. |
Hash-Tables-and-Hashing Functions.md
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| 11 | [Switzerland-Berne] | | ||
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| So to find an item we first go to the bucket then compare keys. This is a popular method, and if link list is used the hash never fills up. The cost for `get(k)` is on average `O(n)` where n is the number of keys in the bucket, total number of keys be N. |
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So to find an item To find an item,
then compare keys. and then we compare keys.
if link list if a list of links
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Done. |
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| ``` | ||
| :rocket: [Run Code](https://repl.it/CVt1) | ||
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@atjonathan, you meant the repl link right?
LGTM 👍 |
LGTM 👍Let's |
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merged commit 
* First Draft of Hashing * Updated Hash-Tables-and-Hashing-Functions.md * Updated Hash-Tables-and-Hashing-Functions.md * Updated Hash-Tables-and-Hashing-Functions.md * Grammar corrections * Grammar corrections * Updated Hash-Tables-and-Hashing-Functions.md
* First Draft of Hashing * Updated Hash-Tables-and-Hashing-Functions.md * Updated Hash-Tables-and-Hashing-Functions.md * Updated Hash-Tables-and-Hashing-Functions.md * Grammar corrections * Grammar corrections * Updated Hash-Tables-and-Hashing-Functions.md
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Compiled the first draft on hashing. let me know if I should add anything else.