Merge pull request deutranium#87 from Hamzakam/optimised-school-method

Created Readme.md for Optimised School Method in Primality tests.

Author: deutranium

primalityTest/optimisedSchoolMethod/README.md

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+# Optimised School Method
+
+ - Checks whether a Given Positive Integer is Prime or not.
+ - Time Complexity:
+	 - Worst Case Complexity:O(√n)
+	 - Best Case Complexity:O(1)
+	 - Average Case Complexity:O(√n)
+- Worst Case Space Complexity:O(1)
+
+### Logic
+
+ 1. Firstly We Only check till √n numbers from 3.
+ 2. We further Optimised the Algorithm by observing the pattern that all Prime Numbers are of the Form 6k ± 1 with exception of 1 and 2.
+ 3. We check whether all (i+6)<sup>th</sup> number are divisible by given number and iterate till the &Sqrt;n<sup>th</sup> number.
+ 4. Pseudo Code:
+		
+
+	    function is_prime(n)
+	        if n ≤ 3 then
+	            return n > 1
+	        else if n mod 2 = 0 or n mod 3 = 0
+	            return false
+    
+        let i ← 5
+        while i × i ≤ n do
+            if n mod i = 0 or n mod (i + 2) = 0
+               return false
+            i ← i + 6
+    
+        return true
+###  Instruction for Running code:
+
+- Python
+    ```	
+    python3 optimisedSchoolMethod.py
+    ```