My Question is that what will be the effect of number of iteration in Robin miller algo sometimes it produce correct answer after passing 0 or 1 iteration sometimes it need upto 8 iteration whats the reason ?? i got AC using 1 iteration in PON (spoj) while i got AC using 8 iteration in http://www.codechef.com/MAY13/problems/WITMATH(may challenge) here is the algorithm Algorithm
Input :A number N to be tested and a variable iteration-the number of 'a' for which algorithm will test N. Output :0 if N is definitely a composite and 1 if N is probably a prime.
Write N as For each iteration Pick a random a in [1,N-1] x = mod n if x =1 or x = n-1 Next iteration for r = 1 to s-1 x = mod n if x = 1 return false if x = N-1 Next iteration return false return true
