Miller_Rabin素数判断

 1 #include <cstdio>
 2 #include <iostream>
 3 #include <algorithm>
 4 #include <cstring>
 5 #include <cmath>
 6 using namespace std;
 7 const int Save = 2;
 8 int N, cnt; bool Isprime = false;
 9 typedef unsigned long long LL;
10 LL S = 2;
11 LL modular_multi(LL x, LL y, LL mo){
12     LL t;
13     x %= mo;
14     for(t = 0; y; x = (x << 1) % mo, y >>= 1)
15         if (y & 1)
16             t = (t + x) % mo;
17     return t;
18 }
19 LL modular_exp(LL num, LL t, LL mo){
20     LL ret = 1, temp = num % mo;
21     for(;t;t >>= 1, temp = modular_multi(temp, temp, mo)) //56.58
22         if (t & 1)
23             ret = modular_multi(ret, temp, mo);
24     return ret;
25 }
26 bool miller_rabbin(LL n){
27     if (n == 2) return true;
28     if (n < 2 || !(n & 1)) return false;
29     int t = 0;
30     LL a, x, y, u = n-1;
31     while((u & 1) == 0) t ++,u >>= 1;
32     for(int i = 0; i < S; i ++){
33         a = rand() % (n - 1) + 1;
34         x = modular_exp(a, u, n);
35         for(int j = 0; j < t; j ++){
36             y = modular_multi(x, x, n);
37             if (y == 1 && x != 1 && x != n - 1)
38                 return false;
39             x = y;
40         }
41         if (x != 1)
42             return false;
43     }
44     return true;
45 }
46 void read(LL &x){
47     x = 0; int sig = 1; char ch = getchar();
48     while(!isdigit(ch)) { if(ch == ‘-‘) sig = -1; ch = getchar(); }
49     while(isdigit(ch)) x = 10 * x + ch - ‘0‘, ch = getchar();
50     x *= sig; return ;
51 }
52 bool init(){
53     cin >> N;
54     if(N == 0) return false;
55     cnt = 0;
56     return true;
57 }
58 void work(){
59     LL a;
60     while(N --){
61         read(a);
62         if(miller_rabbin(a)) cnt ++;
63     }
64     return ;
65 }
66 void print(){
67     printf("%d\n", cnt);
68     return ;
69 }
70 int main(){
71     while(init()){
72         work();
73         print();
74     }
75     return 0;
76 }