add Week 1 PA

Author: SSQ

Programming Assignment 1/karatsuba.py

@@ -0,0 +1,18 @@
+#version 2.7.6
+def karatsuba(num1, num2):
+ num1Str = str(num1)
+ num2Str = str(num2)
+ if (num1 < 10) or (num2 < 10):
+ return num1*num2
+
+ maxLength = max(len(num1Str), len(num2Str))
+ splitPosition = maxLength / 2
+ high1, low1= int(num1Str[:-splitPosition]), int(num1Str[-splitPosition:])
+ high2, low2= int(num2Str[:-splitPosition]), int(num2Str[-splitPosition:])
+ z0 = karatsuba(low1, low2)
+ z1 = karatsuba((low1 + high1), (low2 + high2))
+ z2 = karatsuba(high1, high2)
+
+ return (z2*10**(2*splitPosition)) + ((z1-z2-z0)*10**(splitPosition))+z0
+
+