SPOJ Prime or Not - 快速乘 - 快速幂

Given the number, you are to answer the question: "Is it prime?"

Solutions to this problem can be submitted in C, C++, Pascal, Perl, Python, Ruby, Lisp, Hask, Ocaml, Prolog, Whitespace, Brainf**k and Intercal only.

Input

t – the number of test cases, then t test cases follows. [t <= 500]
Each line contains one integer: N [2 <= N <= 2^63-1]

Output

For each test case output string "YES" if given number is prime and "NO" otherwise.

Example

Input:
5
2
3
4
5
6

Output:
YES
YES
NO
YES
NO

---

　　题目大意是说，给你一个能够用有符号64位整型存储的数，判断它是否是素数。

　　用费马小定理，多次随机生成一个底数a，然后n - 1次幂，判断模n意义下是否是1。

　　为了充分表示对rand()的嫌弃，于是手写了一个随机数生成器。详细请见[here]

Code

 /**
  * SPOJ
  * Problem#PON
  * Accepted
  * Time:180ms
  * Memory:15360k
  */
 #include<iostream>
 #include<cstdio>
 #include<cctype>
 #include<cmath>
 #include<ctime>
 #include<cstring>
 #include<cstdlib>
 #include<fstream>
 #include<sstream>
 #include<algorithm>
 #include<map>
 #include<set>
 #include<queue>
 #include<vector>
 #include<stack>
 using namespace std;
 typedef bool boolean;
 #define INF 0xfffffff
 #define smin(a, b) a = min(a, b)
 #define smax(a, b) a = max(a, b)
 template<typename T>
 inline boolean readInteger(T& u){
     char x;
     ;
     );
     )  {
         ungetc(x, stdin);
         return false;
     }
     if(x == '-'){
         x = getchar();
         aFlag = -;
     }
     ) + (u << ) + x - ');
     ungetc(x, stdin);
     u *= aFlag;
     return true;
 }

 #define LL long long

 typedef class Random {
     public:
         unsigned int pre;
         unsigned int seed;

         Random():pre(), seed((unsigned) time (NULL)) {    }
         Random(), seed(seed) {    }

         /**
          * Generate a random number.
          * @return this function will return the random number it gernerated
          */
         unsigned int rand() {
 //            unsigned int ret = (seed * 7361238 + seed % 20037 * 1244 + pre * 12342 + 378211) * (seed + 134543);
 //            unsigned int ret = (seed * 7361238 + seed % 20037 * 1244 + pre * 12342 + 378211 + time(NULL) * pre) * (seed + 134543);
             unsigned int ret;
             )
                 ret = (seed *  + seed %  *  + pre *  + (time(NULL) * (pre *  + seed *  + )) + );
             else
                 ret = (seed *  + seed %  *  + pre *  + (time(NULL) * (pre *  + seed *  + )) + );
             pre = seed;
             seed = ret;
             return ret;
         }
 }Random;

 inline void setLLhighBit(long long& x, int a) {
     int* p = (int*)&x;
     *(p + ) = a;
 }

 inline void setLLlowBit(long long& x, int a) {
     int* p = (int*)&x;
     *p = a;
 }

 inline void cleanLLSignFlag(long long& a) {
     a &= (1ull << ) - ;
 }

 template<typename T>
 T mul_mod(T a, T b, T& moder) {
     )    return a;
     T temp = mul_mod(a, b >> , moder);
     )    return (((temp + temp) % moder) + a) % moder;
     return (temp + temp) % moder;
 }

 template<typename T>
 T pow_mod(T a, T pos, T& moder) {
     )    return a;
     T temp = pow_mod(a, pos >> , moder);
     )    return mul_mod(mul_mod(temp, temp, moder), a, moder);
     return mul_mod(temp, temp, moder);
 }

 int T;
 LL n;
 Random r;

 inline void work() {
     readInteger(n);
     ) == ) {
         )    puts("YES");
         else puts("NO");
         return;
     }
     unsigned int l, h;
     LL a, r1;
     ; t < ; t++) {
         l = r.rand();
         h = r.rand();
         setLLhighBit(a, h);
         setLLlowBit(a, l);
         cleanLLSignFlag(a);
         a = (a % (n - )) + ;
         r1 = pow_mod(a, n - , n);
         ) {
             puts("NO");
             return;
         }
     }
     puts("YES");
 }

 int main() {
     readInteger(T);
     while(T--) {
         work();
     }
     ;
 }