ProjectEuler654

我,ycl:BM是什么早就忘了!

毕老爷:那你们可以做一做这道题练练BM板子啊。

传送门

 1 //Achen
 2 #include<bits/stdc++.h>
 3 #define For(i,a,b) for(int i=(a);i<=(b);i++)
 4 #define Rep(i,a,b) for(int i=(a);i>=(b);i--)
 5 #define Formylove return 0
 6 const int N=1e5+7,p=1e9+7;
 7 typedef long long LL;
 8 typedef double db;
 9 using namespace std;
10 int n,m;
11 LL f[15007][5007];
12 
13 template<typename T> void read(T &x) {
14     char ch=getchar(); T f=1; x=0;
15     while(ch!='-'&&(ch<'0'||ch>'9')) ch=getchar();
16     if(ch=='-') f=-1,ch=getchar();
17     for(;ch>='0'&&ch<='9';ch=getchar()) x=x*10+ch-'0'; x*=f;
18 }
19 
20 int main() {
21     freopen("1.in","r",stdin);
22     //freopen("biao.in","w",stdout);
23     read(m); read(n);
24     For(i,1,m) f[1][i]=1;
25     For(i,1,n) {
26         if(i>1) For(j,1,m) f[i][j]=f[i-1][m-j];
27         For(j,1,m) f[i][j]=(f[i][j]+f[i][j-1])%p;
28     }
29     printf("%lld\n",f[14555][m]);
30     //printf("%d\n",n);
31     //For(i,1,n) printf("%lld ",f[i][m]);
32     //printf("%lld\n",f[n][m]);
33     Formylove;
34 }
n^2暴力
//Achen
#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<vector>
#include<cstdio>
#include<queue>
#include<cmath>
#include<set>
#include<map>
#define Formylove return 0
#define For(i,a,b) for(int i=(a);i<=(b);i++)
#define Rep(i,a,b) for(int i=(a);i>=(b);i--)
const int N=15007,p=1e9+7;
typedef long long LL;
typedef double db;
using namespace std;
int n,cnt,fail[N];
vector<LL>f[N];
LL a[N],delta[N];

template<typename T>void read(T &x)  {
    char ch=getchar(); x=0; T f=1;
    while(ch!='-'&&(ch<'0'||ch>'9')) ch=getchar();
    if(ch=='-') f=-1,ch=getchar();
    for(;ch>='0'&&ch<='9';ch=getchar()) x=x*10+ch-'0'; x*=f;
}

LL ksm(LL a,LL b) {
    LL rs=1,bs=a%p;
    while(b) {
        if(b&1) rs=rs*bs%p;
        bs=bs*bs%p;
        b>>=1;
    }
    return rs;
}

#define ANS
int main() {
#ifdef ANS
    freopen("biao.in","r",stdin);
    freopen("shizi.out","w",stdout);
#endif
    read(n);
    For(i,1,n) read(a[i]);
    For(i,1,n) {
        LL tp=0; int up=f[cnt].size();
        For(j,0,up-1) tp=(tp+f[cnt][j]*a[i-j-1]%p)%p;
        if(tp==a[i]) continue;
        delta[i]=(a[i]-tp+p)%p;
        fail[cnt]=i;
        ++cnt;
        if(cnt==1) {
            f[cnt].resize(i);
            continue;
        }
        LL mul=delta[i]*ksm(delta[fail[cnt-2]],p-2)%p,fmul=(p-mul)%p;
        f[cnt].resize(i-fail[cnt-2]-1);
        f[cnt].push_back(mul);
        up=f[cnt-2].size();
        For(j,0,up-1) f[cnt].push_back(fmul*f[cnt-2][j]%p);
        up=f[cnt-1].size();
        if(f[cnt].size()<f[cnt-1].size()) f[cnt].resize(up);
        For(j,0,up-1) f[cnt][j]=(f[cnt][j]+f[cnt-1][j])%p; 
    }
    int up=f[cnt].size();
    printf("%d\n",up);
    For(i,0,up-1) printf("%lld ",f[cnt][i]);
    Formylove;
}
BM出递推
 1 //Achen
 2 #include<bits/stdc++.h>
 3 #define For(i,a,b) for(int i=(a);i<=(b);i++)
 4 #define Rep(i,a,b) for(int i=(a);i>=(b);i--)
 5 #define Formylove return 0
 6 const int N=1e5+7,p=1e9+7;
 7 typedef long long LL;
 8 typedef double db;
 9 using namespace std;
10 int cnt;
11 LL A[N],f[N],n;
12 
13 template<typename T> void read(T &x) {
14     char ch=getchar(); T f=1; x=0;
15     while(ch!='-'&&(ch<'0'||ch>'9')) ch=getchar();
16     if(ch=='-') f=-1,ch=getchar();
17     for(;ch>='0'&&ch<='9';ch=getchar()) x=x*10+ch-'0'; x*=f;
18 }
19 
20 LL rs[N],bs[N],tp[N];
21 void cheng(LL a[],LL b[]) {
22     For(i,0,cnt*2) tp[i]=0;
23     For(i,0,cnt-1) For(j,0,cnt-1)
24         (tp[i+j]+=a[i]*b[j])%=p;
25     Rep(i,cnt*2-2,cnt) if(tp[i])
26         For(j,0,cnt-1) 
27             (tp[i-j-1]+=A[j]*tp[i]%p)%=p;
28     For(i,0,cnt-1) a[i]=tp[i];
29 }
30 
31 void ksm(LL b) {
32     while(b) {
33         if(b&1) cheng(rs,bs);
34         cheng(bs,bs);
35         b>>=1;
36     }
37 }
38 
39 int main() {
40     freopen("shizi.out","r",stdin);
41     //freopen("shizi.out","w",stdout);
42     read(cnt);
43     For(i,0,cnt-1) read(A[i]);
44     read(n);
45     rs[0]=1; bs[1]=1; ksm(n-1);
46     For(i,1,cnt) read(f[i]);
47     LL ans=0;
48     For(i,0,cnt-1) ans=(ans+f[i+1]*rs[i]%p)%p;
49     printf("%lld\n",ans);
50     Formylove;
51 }
多项式取模

 

posted @ 2019-03-12 19:34  啊宸  阅读(193)  评论(0编辑  收藏  举报