From 3677ae08e538fcc927c6b24fb82b355af21a97fd Mon Sep 17 00:00:00 2001
From: mikelfried <mikelfried@gmail.com>
Date: Thu, 27 Dec 2018 18:00:39 +0200
Subject: [PATCH 1/4] avrage.py

calculate and print the avrage of number list.
---
 Maths/avrage.py | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
 create mode 100644 Maths/avrage.py

diff --git a/Maths/avrage.py b/Maths/avrage.py
new file mode 100644
index 000000000000..ee102ea687ce
--- /dev/null
+++ b/Maths/avrage.py
@@ -0,0 +1,14 @@
+def avrage(nums):
+    sum = 0
+    n = 0
+    for x in nums:
+      sum += x
+      n += 1
+    avg = sum / n
+    print(avg)
+
+def main():
+  avrage([2, 4, 6, 8, 20, 50, 70])
+
+if __name__ == '__main__':
+  main()

From ae933ba2d38b1486bdde74e4fe3c280c6203ba27 Mon Sep 17 00:00:00 2001
From: Michael Fried <mikelfried@gmail.com>
Date: Sat, 29 Dec 2018 22:03:16 +0200
Subject: [PATCH 2/4] Update base64_cipher.py

encoding and decoding base64 without any module.
---
 ciphers/base64_cipher.py | 65 ++++++++++++++++++++++++++++++++++++----
 1 file changed, 59 insertions(+), 6 deletions(-)

diff --git a/ciphers/base64_cipher.py b/ciphers/base64_cipher.py
index 975f24d6bb5d..fa3451c0cbae 100644
--- a/ciphers/base64_cipher.py
+++ b/ciphers/base64_cipher.py
@@ -1,11 +1,64 @@
-import base64
+def encodeBase64(text):
+    base64chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
+    
+    r = "" #the result
+    c = 3 - len(text) % 3 #the length of padding
+    p = "=" * c #the padding
+    s = text + "\0" * c #the text to encode
+    
+    i = 0   
+    while i < len(s):
+        if i > 0 and ((i / 3 * 4) % 76) == 0:
+            r = r + "\r\n"
+        
+        n = (ord(s[i]) << 16) + (ord(s[i+1]) << 8 ) + ord(s[i+2])
+        
+        n1 = (n >> 18) & 63
+        n2 = (n >> 12) & 63
+        n3 = (n >> 6)  & 63
+        n4 = n & 63
+        
+        r += base64chars[n1] + base64chars[n2] + base64chars[n3] + base64chars[n4]
+        i += 3
+
+    return r[0: len(r)-len(p)] + p
+    
+def decodeBase64(text):
+    base64chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
+    s = ""
+    
+    for i in text:
+        if i in base64chars:
+            s += i
+            c = ""
+        else:
+            if i == '=':
+                c += '='
+    
+    p = ""
+    if c == "=":
+        p = 'A'
+    else:
+        if c == "==":
+            p = "AA"
+    
+    r = ""
+    s = s + p
+   
+    i = 0
+    while i < len(s):
+        n = (base64chars.index(s[i]) << 18) +  (base64chars.index(s[i+1]) << 12) +  (base64chars.index(s[i+2]) << 6) +base64chars.index(s[i+3])
+        
+        r += chr((n >> 16) & 255) + chr((n >> 8) & 255) + chr(n & 255)
+        
+        i += 4
+    
+    return r[0: len(r) - len(p)]
 
 def main():
-    inp = input('->')
-    encoded = inp.encode('utf-8') #encoded the input (we need a bytes like object)
-    b64encoded = base64.b64encode(encoded) #b64encoded the encoded string
-    print(b64encoded)
-    print(base64.b64decode(b64encoded).decode('utf-8'))#decoded it
+    print(encodeBase64("WELCOME to base64 encoding"))
+    print(decodeBase64(encodeBase64("WELCOME to base64 encoding")))
+    
 
 if __name__ == '__main__':
     main()

From 1512fdddcc1dbe96e1a9991256780cbe0f51e2b4 Mon Sep 17 00:00:00 2001
From: Michael Fried <mikelfried@gmail.com>
Date: Sat, 29 Dec 2018 22:08:08 +0200
Subject: [PATCH 3/4] Update and rename avrage.py to average.py

---
 Maths/{avrage.py => average.py} | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
 rename Maths/{avrage.py => average.py} (73%)

diff --git a/Maths/avrage.py b/Maths/average.py
similarity index 73%
rename from Maths/avrage.py
rename to Maths/average.py
index ee102ea687ce..dc70836b5e83 100644
--- a/Maths/avrage.py
+++ b/Maths/average.py
@@ -1,4 +1,4 @@
-def avrage(nums):
+def average(nums):
     sum = 0
     n = 0
     for x in nums:
@@ -8,7 +8,7 @@ def avrage(nums):
     print(avg)
 
 def main():
-  avrage([2, 4, 6, 8, 20, 50, 70])
+  average([2, 4, 6, 8, 20, 50, 70])
 
 if __name__ == '__main__':
   main()

From 9c39006bbf25459e5987fd064c1d77f4338083b6 Mon Sep 17 00:00:00 2001
From: Michael Fried <mikelfried@gmail.com>
Date: Sat, 19 Jan 2019 22:28:51 +0200
Subject: [PATCH 4/4] update find_lcm algorithm

I made find_lcm more efficient form O(num1*num2) to O(min{num1,num2}).
---
 Maths/find_lcm.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/Maths/find_lcm.py b/Maths/find_lcm.py
index 58beb3e37649..126242699ab7 100644
--- a/Maths/find_lcm.py
+++ b/Maths/find_lcm.py
@@ -1,10 +1,11 @@
 def find_lcm(num_1, num_2):
     max = num_1 if num_1 > num_2 else num_2
+    lcm = max
     while (True):
-        if ((max % num_1 == 0) and (max % num_2 == 0)):
+        if ((lcm % num_1 == 0) and (lcm % num_2 == 0)):
             break
-        max += 1
-    return max
+        lcm += max
+    return lcm
 
 
 def main():