A simple number of topics in the finals of the Guangzhou Engineering School Competition

Topic Link: F: I am a good person, the main topic: give you two number N and M, ask you how many pairs of positive integers to greatest common divisor is n, least common multiple is M.

Because 1 <= N, M <= 10000000000, the violence law definitely timed out, the game I also thought of the N and M decomposition, factorization and corresponding index stored in the map, the idea is correct, can not think of some details of the problem is not considered thoughtful, in no judgment N and M whether coprime Before blindly to decompose them, the result of course is WA a number of times, I am still struggling to ponder whether the idea is wrong, until today and wencong discussion to find this flaw. With the simple decomposition method has been able to within the time limit range, and then I use the prime sieve method to generate a prime number and then to decompose N and m significantly faster:

The code is as follows:

1#include <cstdio>2#include <cstring>3#include <string>4#include <cmath>5#include <cstdlib>6#include <vector>7#include <map>8#include <queue>9#include <algorithm>Ten#include <iostream> One using namespacestd; AtypedefLong LongLL; - ConstLL inf=0x3fffffff; - ConstLL maxn=100005; the  - BOOLVIS[MAXN]; - intPrime_num; -LL prime[10004]; + intInit (LL n=MAXN) - { +     intC=0; A      for(LL i=2; i<=n; ++i) at         if(!Vis[i]) { -prime[++c]=i; -              for(LL j= i*i; j<=n; j+=i) vis[j]=1; -         } -     returnprime_num=C; - } in  - voidFactor (LL N, map<ll,ll> &m) to { +LL tmp= sqrt (n+0.5), I; -      for(i=1; I<=prime_num && prime[i]<=tmp; ++i) the         if(n%prime[i]==0){ *             intnum=1; $              while((N/=prime[i])%prime[i]==0)  ++num;Panax Notoginsengm[prime[i]]=num; -         } the     if(n!=1) m[n]=1; + } A  the intMain () + { -     intT; $ LL x, y; $scanf"%d",&t); - Init (); -      while(t--){ thescanf"%lld%lld",&x,&y); -         if(x==y) {WuyiPuts"1"); the             Continue; -         } Wu         if(x>y) Swap (x, y); -         if(y%x) { AboutPuts"0"); $             Continue; -         } -Map<ll,ll>m1,m2; - factor (X,M1); A factor (Y,M2); +Map<ll,ll>:: iterator it; the  -LL ans=1; $          for(it= m2.begin (); It!=m2.end (); + +it) the             if(It->second! = M1[it->first]) ans<<=1; theprintf"%lld\n",ans>>1); the     } the     return 0; -}

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A simple number of topics in the finals of the Guangzhou Engineering School Competition