In this vide , why we doing A%p it will not change the solution . according to fermat little theorm , a^b =a^(b%(p-1) ) not in base (that is a)
Fermat Little Theorm
hello @premkiryanastore2016
we know x^(p-1) mod p => 1 if p is prime number…fermant little theorem
now to calculate (a^b) mod p .
we can write b = (p-1) + (p-1) + (p-1) … + k
where k is remainder we are left with. i.e k=b%(p-1)
substituting value of b
(a^b)mod p = a^(p-1 + p-1 + p-1 + p-1 … + k) mod p
now using property a^(x+y) => a^x * a^y
=> ( a^(p-1) * a^(p-1) * a^(p-1) … a^k )mod p
now we know a^(p-1) mod p =1
=> 1 * 1 * 1 …a^k mod p
=> a^k mod p
substituting value of k
=> a^(b%(p-1) ) mod p