HDU 3864 d_num Miller Rabin prime number judgment + Pollard ROV big integer Decomposition

Link: http://acm.hdu.edu.cn/showproblem.php? PID = 1, 3864

A number N (1 <= n <10 ^ 18) is given. If n has only four dikes, three dikes except 1 are output.

Idea: the prime factor decomposition of large numbers can only be performed using random algorithms Miller Rabin and pollard_rock. The accuracy is guaranteed when there are many tests.

Code:

# Include <iostream> # include <cstdio> # include <cstring> # include <cmath> # include <map> # include <cstdlib> # include <queue> # include <stack> # include <vector> # include <ctype. h> # include <algorithm> # include <string> # include <set> # include <ctime> # define PI ACOs (-1.0) # define INF 0x7fffffff # define EPS 1e-8 # define maxn 50005 typedef _ int64 ll; typedef unsigned long ull; using namespace STD; ll factor [100]; int T = 0; ll mul_mod (ll a, LL B, ll N) {A = A % N; B = B % N; ll s = 0; while (B) {If (B & 1) S = (S + a) % N; A = (a <1) % N; B = B> 1 ;}return s ;} ll pow_mod (ll a, LL B, ll N) // evaluate a ^ B % N {A = A % N; ll S = 1; while (B) {If (B & 1) S = mul_mod (s, A, n); A = mul_mod (a, a, n); B = B> 1 ;} return s;} bool isprime (ll n, ll times) {If (n = 2) return 1; if (n <2 |! (N & 1) return 0; ll A, u = n-1, X, Y; int T = 0; while (U % 2 = 0) {T ++; u/= 2;} srand (100); For (INT I = 0; I <times; I ++) {A = rand () % (n-1) + 1; X = pow_mod (A, U, N); For (Int J = 0; j <t; j ++) {Y = mul_mod (x, x, N ); if (y = 1 & X! = 1 & X! = N-1) return false; // must not X = y;} If (y! = 1) return false;} return true;} ll gcd (ll a, LL B) {if (a = 0) return 1; if (a <0) return gcd (-a, B); return B = 0? A: gcd (B, A % B);} ll pollard_rov (ll n, ll c) // pollard_rov algorithm, find the N factor {ll I = 1, J, k = 2, X, Y, D, P; X = rand () % N; y = x; while (true) {I ++; X = (mul_mod (X, x, n) + C) % N; If (y = x) return N; If (Y> X) P = Y-X; else P = x-y; D = gcd (p, n); If (D! = 1 & D! = N) return D; if (I = k) {Y = x; k + = K ;}} void factor (LL N) {If (isprime (n, 20) {factor [t ++] = N; return;} ll p = N; while (P> = N) P = pollard_rock (p, Rand () % (n-1) + 1); factor (p); factor (N/P);} void solve (ll a) {if (a = 1) {printf ("is not a d_num \ n"); return;} t = 0; factor (a); sort (factor, factor + t ); if (t = 2) {If (factor [0]! = Factor [1]) {printf ("% i64d % i64d % i64d \ n", factor [0], factor [1], );} else printf ("is not a d_num \ n");} else if (t = 3) {If (factor [0] = factor [1] & factor [1] = factor [2]) printf ("% i64d % i64d % i64d \ n ", factor [0], factor [0] * factor [1], a); else printf ("is not a d_num \ n ");} else printf ("is not a d_num \ n");} int main () {ll A; while (~ Scanf ("% i64d", & A) {solve (a) ;}return 0 ;}