2018 ACM-ICPC Chinese University student Program design Competition online B. goldbach-Millerabine Prime number Determination (large prime)

A number of years ago, when the problem can be written or super happy, although it is a board problem. Always forget to write a blog, memo.

Miller's big Prime, about what Millerabine is, the portal. Learn about: biubiubiu~

B. Goldbach

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See test instructions yourself, directly affixed to the code.

Code:

1#include <iostream>2#include <cstdio>3#include <cstring>4#include <cmath>5#include <cstdlib>6#include <algorithm>7#include <queue>8#include <vector>9#include <stack>Ten using namespacestd; Onetypedef unsignedLong Longll; A Const intmaxn=1e9+Ten; - Const Doubleeps=1e-7; -ll Add_mod (ll a,ll b,ll MoD)//fast multiplication based on the theory of two points of fast power the { -ll ans=0;//due to the large and fast power overflow of the modulus -      while(b)//You must use this method -     { +         if(b&1)//I'm writing a non-recursive version here. -ans= (ans+a)%MoD; +a=a*2%MoD; Ab>>=1; at     } -     returnans; - } -  -ll Pow_mod (ll a,ll n,ll MoD)//Rapid Power Recursive version - { in     if(n>1) -     { toll Tmp=pow_mod (a,n>>1, MoD)%MoD; +tmp=Add_mod (tmp,tmp,mod); -         if(n&1) tmp=Add_mod (tmp,a,mod); the         returntmp; *     } $     returnA;Panax Notoginseng } -  the BOOLMiller_rabbin (ll n,ll a)//Millerabine prime judgment function body + { All d=n-1, s=0, I; the      while(! (d&1))//first calculate the (2^s) *d. +     { -d>>=1; $s++; $     } -ll T=pow_mod (a,d,n);//A^d take a time to judge -     if(t==1|| t==-1)//one or minus a can declare that this could be prime the         return 1; -      for(i=0; i<s; i++)//if not, continue to multiply the S 2 .Wuyi     { the         if(t==n-1)//(n-1) * (n-1)%n=1 This step is to optimize -             return 1; WuT=add_mod (T,t,n);//Quick Ride -     } About     return 0; $ } -  - intIs_prime (ll N) - { All i,tab[4]= {3,4,7, One};//any integer in [1,n] should have been taken +      for(i=0; i<4; i++)//but generally these few numbers are enough to not need too many group tests the     { -         if(n==Tab[i]) $             return 1;//Small Judgment Small optimization ~ the         if(!n%Tab[i]) the             return 0; the         if(N>tab[i] &&!Miller_rabbin (N,tab[i])) the             return 0; -     } in     return 1; the } the ll Max (ll A,ll b) About { the     returnA>b?a:b; the } the intMain () + { -     intT; thescanf"%d",&t);Bayi      while(t--) the     { the ll N; -scanf"%llu",&n); -         if(n==4) theprintf"2 2\n"); the         Else the         { the              for(LL i=2; i<=n/2; ++i) -             { the                 if(Is_prime (i) &&is_prime (ni)) the                 { theprintf"%llu%llu\n", i,n-i);94                      Break; the                 } the             } the         }98     } About}

At that time, my teammates helped me with the D bug, and he ignored me Now ((?_?))

Uncomfortable

2018 ACM-ICPC Chinese University student Program design Competition online B. goldbach-Millerabine Prime number Determination (large prime)