COGS 2294. [HZOI 2015] 释迦

额,其实就是裸的三模数NTT,上一篇已经说过了

哦,还有一个就是对乘起来炸long long的数取模,用long double之类的搞一下就好,精度什么的,,(看出题人心情??)

  1 #include<cstdio>
  2 #include<cstdlib>
  3 #include<algorithm>
  4 #include<cstring>
  5 #define LL long long
  6 #define N 300005
  7 using namespace std;
  8 inline int ra()
  9 {
 10     int x=0; char ch=getchar();
 11     while (ch<'0' || ch>'9') ch=getchar();
 12     while (ch>='0' && ch<='9') {x=x*10+ch-'0'; ch=getchar();}
 13     return x;
 14 }
 15 
 16 const int mod=23333333;
 17 const int M[]={998244353,1004535809,469762049};
 18 const int G[]={3,3,3};
 19 const LL _M=(LL)M[0]*M[1];
 20 
 21 LL ksm(LL a, int b, int P)
 22 {
 23     LL sum=1;
 24     for (;b;b>>=1,a=a*a%P)
 25         if (b&1) sum=sum*a%P;
 26     return sum;
 27 }
 28 /*LL mul(LL a, LL b, LL p)
 29 {
 30     a%=p; b%=p;
 31     return ((a*b-(LL)((LL)((long double)a/p*b+1e-3)*p))%p+p)%p;
 32 }
 33 const int m1=M[0],m2=M[1],m3=M[2];
 34 const int inv1=ksm(m1%m2,m2-2,m2),inv2=ksm(m2%m1,m1-2,m1),inv12=ksm(_M%m3,m3-2,m3);
 35 int CRT(int a1, int a2, int a3)
 36 {
 37     LL A=(mul((LL)a1*m2%_M,inv2,_M)+mul((LL)a2*m1%_M,inv1,_M))%_M;
 38     LL k=((LL)a3+m3-A%m3)*inv12%m3;
 39     return (k*(_M%mod)+A)%mod;
 40 }*/
 41 
 42 inline LL mul(LL a,LL b,LL p){
 43   a%=p; b%=p;
 44   return ((a*b-(LL)((LL)((long double)a/p*b+1e-3)*p))%p+p)%p;
 45 }
 46 
 47 const int m1=M[0],m2=M[1],m3=M[2];
 48 const int inv1=ksm(m1%m2,m2-2,m2),inv2=ksm(m2%m1,m1-2,m1),inv12=ksm(_M%m3,m3-2,m3);
 49 inline int CRT(int a1,int a2,int a3){
 50   LL A=(mul((LL)a1*m2%_M,inv2,_M)+mul((LL)a2*m1%_M,inv1,_M))%_M;
 51   LL k=((LL)a3+m3-A%m3)*inv12%m3;
 52   return (k*(_M%mod)+A)%mod;
 53 }
 54 int rev[N];
 55 struct NTT{
 56     int num,P,G;
 57     int w[2][N];
 58     void pre(int _P, int _G, int n)
 59     {
 60         num=n; P=_P; G=_G;
 61         int g=ksm(G,(P-1)/num,P);
 62         w[1][0]=1; for (int i=1; i<n; i++) w[1][i]=(LL)w[1][i-1]*g%P;
 63         w[0][0]=1; for (int i=1; i<n; i++) w[0][i]=w[1][n-i];
 64     }
 65     void FFT(int *a, int n, int f)
 66     {
 67         for (int i=0; i<n; i++) if (i<rev[i]) swap(a[i],a[rev[i]]);
 68         for (int i=1; i<n; i<<=1)
 69             for (int j=0; j<n; j+=(i<<1))
 70                 for (int k=0; k<i; k++)
 71                 {
 72                     int x=a[j+k],y=(LL)w[f][num/(i<<1)*k]*a[i+j+k]%P;
 73                     a[j+k]=(x+y)%P; a[i+j+k]=(x-y+P)%P;
 74                 }
 75         if (!f) for (int i=0,inv=ksm(n,P-2,P); i<n; i++) a[i]=(LL)a[i]*inv%P;
 76     }
 77 }ntt[3];
 78 
 79 int n,m;
 80 int ans[3][N];
 81 int a[N],b[N],c[N],d[N];
 82 
 83 int main()
 84 {
 85       freopen("annona_squamosa.in","r",stdin); freopen("annona_squamosa.out","w",stdout);
 86     n=ra();
 87     for (int i=0; i<n; i++) a[i]=ra();
 88     for (int i=0; i<n; i++) b[i]=ra();
 89     for (m=1; m<n<<1; m<<=1);
 90     int L=0,x=m>>1; while (!(x&1)) x>>=1,L++;
 91     for (int i=0; i<m; i++) rev[i]=(rev[i>>1]>>1)|((i&1)<<L);
 92 //      for (m=1;m<=2*(n-1);m<<=1);
 93 //    int L=0,x=m; while (x>>=1) L++;
 94 //    for (int i=1;i<=m;i++) rev[i]=(rev[i>>1]>>1)|((i&1)<<(L-1));
 95 //    for (int i=0; i<m; i++) printf("%d ",rev[i]); cout<<endl;
 96     for (int i=0; i<3; i++) ntt[i].pre(M[i],G[i],m);
 97     for (int i=0; i<3; i++)
 98     {
 99         memcpy(c,a,sizeof(int)*(m+5)); memcpy(d,b,sizeof(int)*(m+5));
100         ntt[i].FFT(c,m,1); ntt[i].FFT(d,m,1);
101         for (int j=0; j<m; j++) c[j]=(LL)c[j]*d[j]%ntt[i].P;
102         ntt[i].FFT(c,m,0);
103         for (int j=0; j<m; j++) ans[i][j]=c[j];
104     }
105     for (int i=0; i<n; i++) printf("%d ",CRT(ans[0][i],ans[1][i],ans[2][i]));
106     return 0;
107 }

 

posted @ 2017-05-01 21:39  ws_ccd  阅读(224)  评论(0编辑  收藏  举报