Update README.md

Author: rachleona

README.md

@@ -712,100 +712,15 @@ __code Implementation:__ <p> </p>
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-<b>9. Caesar Cipher </b>
+<b>9. Name </b>
 
-__The challenge:__ <p> Given a string and a shift key, encrypt the string through Caesar Cipher.</p>
-
-__Algorithmic Thinking:__ <p> This is a very simple algorithm that requires only a tiny bit of prerequisite knowledge regarding ASCII, and also some discretion when processing possible over 26 keys. Basically we just need to know that all chracters are stored as numbers in computer memory according to the ASCII standard: https://www.w3schools.com/charsets/ref_html_ascii.asp. And that the modulus function is our friend :)</p>
-
-
-__code Implementation:__ <p>
- 
-So first of all we need to split the string into characters to be processed individually and convert it to ASCII codes. Then we must check whether the character is either uppercase or lowercase(everything else should be kept the same) then add the key to it accordingly. But it is not a simple matter of simply doing ```char + key``` because for example, by shifting X by 3 we should get A. However, X(88) + 3 equals to 91 which is "\[". Thus what we should be doing is:
- 
-```js
-// js has built in String.charCodeAt() method to help us get the ASCII code 
-// https://www.w3schools.com/jsref/jsref_charcodeat.asp
-// the reverse is String.fromCharCode()
-const char = charCodeAt("X")
-const key = 3
-
-const encryptedWrongly = char + key
-
-// uppercase letters start at code 65, ends at 90
-const encryptedCorrectly = 65 + (char + key) % 65
- 
-```
-
-Also taking into account the possibility of >26 keys:
-
-```js
-const encrypted = 65 + (char + key) % 65 % 26
-```
-
-Additional functionality can be added by allowing the argument to be an array of keys:
-
-```js
-const allShifts = [...Array(25).keys()].map( n => n + 1 )
-const cipher = (str, keys=allShifts) => {
- ...
- const res = keys.map( key => {
- ...
- })
-}
-```
+__The challenge:__ <p> </p>
 
-Putting it all together:
 
-```js
-const allShifts = [...Array(26).keys()]
-
-// return all possible shifts if keys not given
-const cipher = (str, keys=allShifts) => {
- const chars = str.split("")
- const res = keys.map( key => {
- return chars.map( c => {
- const char = c.charCodeAt(0)
- if(char > 64 && char < 91)
- {
- return String.fromCharCode(65 + (char + key) % 65 % 26)
- }
- else if(char > 96 && char < 123)
- {
- return String.fromCharCode(97 + (char + key) % 97 % 26)
- }
- else
- {
- return String.fromCharCode(char)
- }
- })
- })
- return res.map( (r, i) => { return { key: keys[i], result: r.join("") } } )
-}
+__Algorithmic Thinking:__ <p> </p>
 
-cipher("JavaScript", [1, 2, 27]) 
-/*[{ key: 1, result: 'KbwbTdsjqu' },
- { key: 2, result: 'LcxcUetkrv' },
- { key: 27, result: 'KbwbTdsjqu' }]*/
- 
-cipher("Something")
-/*[{ key: 1, result: 'Tpnfuijoh' },
- { key: 2, result: 'Uqogvjkpi' },
- { key: 3, result: 'Vrphwklqj' },
- { key: 4, result: 'Wsqixlmrk' },
- ......,
- { key: 20, result: 'Migynbcha' },
- { key: 21, result: 'Njhzocdib' },
- { key: 22, result: 'Okiapdejc' },
- { key: 23, result: 'Pljbqefkd' },
- { key: 24, result: 'Qmkcrfgle' },
- { key: 25, result: 'Rnldsghmf' }
-]
-*/
-```
 
-And that's the easiest encryption ever! Happy Coding!
-</p>
+__code Implementation:__ <p> </p>
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