poj 1811(隨機化素數測試+素因子分解,未解決)
阿新 • • 發佈:2021-08-10
#include<iostream> #include<cstdlib> #include<cstdio> #include<cmath> using namespace std; #define ll long long ll witness(ll a, ll n){ int x, d=1, i = ceil(log(n - 1.0) / log(2.0)) - 1; for ( ; i >= 0; i--) { x = d; d = (d * d) % n; if (d==1 && x!=1&& x!=n-1) return 1; if (((n-1) & (1<<i)) > 0) d = (d * a) % n; } return (d == 1 ? 0 : 1); } ll miller(ll n, ll s = 50){ if (n == 2) return 1; if ((n % 2) == 0) return 0; int j, a; for (j = 0; j < s; j++) { a = rand() * (n-2) / RAND_MAX + 1;// rand()只能隨機產生[0, RAND_MAX)內的整數 // 而且這個RAND_MAX只有32768直接%n的話永遠也產生不了 // [RAND-MAX, n)之間的數 if (witness(a, n)) return 0; } return 1; } int main(){ int t; ll n; scanf("%lld",&t); while(t--){ scanf("%lld",&n); if(miller(n))printf("Prime\n");else printf("%lld\n",n); } bool flag = miller(n); return 0; }