Last M digits of expression A^N
mukesh tiwari
mukeshtiwari.iiitm at gmail.com
Fri Feb 5 15:14:51 EST 2010
Hello everyone. I am kind of new to python so pardon me if i sound
stupid.
I have to find out the last M digits of expression.One thing i can do
is (A**N)%M but my A and N are too large (10^100) and M is less than
10^5. The other approach was repeated squaring and taking mod of
expression. Is there any other way to do this in python more faster
than log N.
def power(A,N,M):
ret=1
while(N):
if(N%2!=0):ret=(ret*A)%M
A=(A*A)%M
N=N//2
return ret
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