给定大素数P，如果求其原根？给出算法描述。并编程实现具体功能。

　　利用随机数生成大素数q，P是形如2*q+1的大素数，P也为素数，若P不为素数，则重新生成大素数q，重复上述步骤。生成随机数g，1<g<p-1，要满足：g^2 mod p!=1, g^q mod p!=1, 则g为P的本原根。-Given a large prime number P, if you find its original roots? Algorithm descr iption is given. And specific programming functions.

Use of random number generation of large prime numbers q, P is of the form 2* q 1 large prime number, P is a prime number, if P is not prime, then regenerate the

NCKU prime q, repeat the above steps. Generate random numbers g, 1 <g <p-1, to meet: g ^ 2 mod p! = 1, g ^ q mod p! = 1, then

P g is the primitive root.