add readme script

README.md

@@ -5,6 +5,102 @@ Python implementation of 30-seconds-of-code.
 
 **Note**:- This is in no way affiliated with the original [30-seconds-of-code](https://github.com/Chalarangelo/30-seconds-of-code/)
 
+### gcd
+
+Calculates the greatest common divisor between two or more numbers/arrays.
+
+The `helperGcdfunction` uses recursion. Base case is when `y` equals `0`. In this case, return `x`. Otherwise, return the GCD of `y` and the remainder of the division `x/y`.
+
+Uses the reduce function from the inbuild module `functools`. Also defines a method `spread` for javascript like spreading of arrays.
+
+```python 
+from functools import reduce
+
+
+def spread(arg):
+    ret = []
+    for i in arg:
+        if isinstance(i, list):
+            ret.extend(i)
+        else:
+            ret.append(i)
+    return ret
+
+
+def gcd(*args):
+    numbers = []
+    numbers.extend(spread(list(args)))
+
+    def _gcd(x, y):
+        return x if not y else gcd(y, x % y)
+
+    return reduce((lambda x, y: _gcd(x, y)), numbers)
+
+```
+
+
+``` python
+gcd(8,36) # 4
+```
+### lcm 
+
+Returns the least common multiple of two or more numbers.
+
+Use the `greatest common divisor (GCD)` formula and the fact that `lcm(x,y) = x * y / gcd(x,y)` to determine the least common multiple. The GCD formula uses recursion.
+
+```python 
+from functools import reduce
+
+
+def spread(arg):
+    ret = []
+    for i in arg:
+        if isinstance(i, list):
+            ret.extend(i)
+        else:
+            ret.append(i)
+    return ret
+
+
+def lcm(*args):
+    numbers = []
+    numbers.extend(spread(list(args)))
+
+    def _gcd(x, y):
+        return x if not y else gcd(y, x % y)
+
+    def _lcm(x, y):
+        return x * y / _gcd(x, y)
+
+    return reduce((lambda x, y: _lcm(x, y)), numbers)
+
+```
+
+
+``` python
+lcm(12, 7) # 84
+lcm([1, 3, 4], 5) # 60
+```
+### spread
+
+Implements javascript's spread syntax as a function. Flattens the list(non-deep) and returns an array.
+
+```python 
+def spread(arg):
+    ret = []
+    for i in arg:
+        if isinstance(i, list):
+            ret.extend(i)
+        else:
+            ret.append(i)
+    return ret
+
+```
+
+
+```python
+spread([1,2,3,[4,5,6],[7],8,9]) # [1,2,3,4,5,6,7,8,9]
+```
 
 ## Credits