Prime Number素数
definition:除了1和本身,不能被任何数分解的数,称为prime,否则称为composite number.
natural number:自然数
even number:偶数
odd number:奇数
判断是否为prime number的方法:trival division, Miller–Rabin primality test,AKS primality test
application:information technology(public key encryption)
哥德巴赫猜想:每个大于2的偶数证书可以表示为两个素数之和
Reference:
https://en.wikipedia.org/wiki...
Fermat Little theorm
如果p是一个素数,对于任何整数a,$a^P-a= b*p .$, where b is an integer.转换成模数运算为:
$a^P==a (mod P)$
For example, if a = 2 and p = 7, then$2^7=128$, $and 128 − 2 = 126 = 7 × 18 $ isan integer multiple of 7.
https://brilliant.org/wiki/fe...
https://en.wikipedia.org/wiki...
The ring Z/nZℤ/nℤ is a field if and only if nn is prime
Abstract algebra
Integer Domains
取模运算中,求解方程组的过程和normal algebra不一样。
zero divisors
https://en.wikipedia.org/wiki...
commutative ring