BZOJ3560: DZY Loves Math V

 1 #include<cstdio>
 2 #include<algorithm>
 3 #include<cmath>
 4 #include<cstring>
 5 using namespace std;
 6 #define rep(i,j,n) for(int i=j;i<=n;i++)
 7 char c;template<class T> inline void read(T&x){for(c=getchar();c<‘0‘||c>‘9‘;c=getchar());for(x=0;c>=‘0‘&&c<=‘9‘;c=getchar())x=x*10+c-‘0‘;};
 8 const int N=10000000,M=664580,mod=1000000007;
 9 int ta,tb,n,x,phi[N+1],p[M];
10 long long tc,td,d[M];
11 bool pd[N+1];
12 void pre(){
13     pd[1]=1;
14     rep(i,2,N){
15         if(!pd[i])p[++p[0]]=i,phi[i]=p[0];
16         for(int j=1,mul;j<=p[0]&&(mul=i*p[j])<=N;j++){
17             pd[mul]=1;phi[mul]=j;
18             if(i%p[j]==0)break;
19         }
20     }
21     rep(i,1,p[0]) d[i]=1;
22     memset(pd,false,sizeof(pd));
23 }
24 int main(){
25     pre();
26     read(n);
27     rep(i,1,n){
28         read(x);
29         while(x>1){
30             ta=phi[x];tb=1;tc=1;
31             while(x%p[ta]==0){
32                 tc=tc*p[ta]%mod;
33                 tb=tb+tc;
34                 if(tb>=mod)tb-=mod;
35                 x/=p[ta];
36             }
37             d[ta]=d[ta]*tb%mod;
38             pd[ta]=true;
39         }
40     }
41     tc=1;td=1;
42     rep(i,1,p[0]) if(pd[i]){
43         tc=tc*(d[i]*(p[i]-1)%mod+1)%mod;
44         td=td*p[i]%mod;
45     }
46     ta=mod-2;
47     while(ta){
48         if(1&ta) tc=tc*td%mod;
49         td=td*td%mod;
50         ta>>=1;
51     }
52     printf("%lld\n",tc);
53 }