Add zine hash tables

README.md

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+Hi person 👋
+
+Here you can find my sketches that explain code with drawings. 🎨

zine_hash-tables/README.md

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+# The magic of Hash Tables
+
+Feel free to [download the printable version](./assets/print.png). Here's also the [original hand-made version](./assets/original.png).
+
+<img src="./assets/print.png" alt="Print Version" width="700">
+
+## Digital Version
+<img src="./assets/0_cover.png" alt="Cover" width="350">
+
+<img src="./assets/1_intro.png" alt="Intro" width="700">
+
+<img src="./assets/2_collisions.png" alt="Collisions" width="700">
+
+<img src="./assets/3_faq.png" alt="FAQ" width="700">
+
+<img src="./assets/4_js.png" alt="JS" width="700">
+
+
+## Written Version
+
+### What it is for
+The most efficient data structure to:
+- Search
+- Insert
+- Delete
+
+Does all of it in O(1) complexity on average (i.e. Takes the same time to
do it, no matter the size of data available)
+
+####  It's used for:
+- Cashing
+- Database searching
+- Sets
+
+### How it works
+An unordered collection of **unique keyes** is mapped to **values** through the process of hashing.
+
+| Take a key | Run it in a hash fn | that generates a hash | add it to the table index (bucket) |
+| ---------- | ------------------- | --------------------- | ---------------------------------- |
+| Portuguese | ✨                  | 2                     | Salut                              |
+| French     | ✨                  | 0                     | Olá                                |
+| English    | ✨                  | 3                     | Hello                              |
+
+#### Hashing is one-way!
+A hash can’t be converted back to its original key.
+
+#### A hash function must:
+- Be fast to run.
+- Uniform distribution.
+- Resolve hash collisions.
+
+### How to handle Collisions?
+It happens when a key corresponds to a hash (index) already taken by another key.
+
+#### Open Addressing
+When a bucket is already taken,
+other buckets are examined until an unused bucket is found.
+
+- 💚 Fast when number of collisions is small.
+- 🚨 Tables can’t be smaller than number of keys.
+
+#### Chaining
+A bucket can take multiple keys with the same index.
+
+- 💚 Good for large number of collisions.
+- 🚨 Wastage of space (some buckets are never used).
+
+### FAQ
+
+#### What is the ideal Load Factor?
+Some say it’s ~0.7. This means a table with 70 items should have ~100 buckets. But it’s a balance...
+
+The emptier the buckets... faster, less collisions but more memory used.
+
+#### What is Dynamic Resize?
+It happens when a table is getting out of balance - it’s too full or too empty. It resizes the table and rehash the keys.
+
+#### What’s the best Hash Function?
+There isn’t a one-fits-all solution. It’s a trade-off between speed and distribution.
+
+**TIP:** When the keys are static use a Perfect Hash Function. * No collisions * No empty buckets *
+
+A good hash function is the secret to an efficient hash table.
+
+#### When should I avoid Hash Tables?
+- Search is not the main operation.
+- Need to iterate over the elements.
+- There are duplicated keys.
+
+### Applying Simple Hash Table Concept in Javascript!
+
+#### 😰If hell
+```js
+if(viewport === 'sm') {
+    fontSize = 1.0;
+} if else (viewport === 'md') {
+    fontSize = 1.2;
+
} // if else ... if else ...
+
+```
+
+#### ⚡️Using key:value mapping
+O(1) - Direct access - no matter the amount of options.
+
+```js
+const sizes = {

+    sm: 1,
+    md: 1.2,
+    lg: 1.2

+};
+
+const fontSize = sizes[viewport];
+```
+
+---
+
+Thank you for reading!