夏夜、

心若平似镜、何题不AC。

HDU 2243 AC自动机+DP+矩阵

好综合的一题啊,AC自动机+DP+非递归矩阵快速幂+二分+逆向思维。

//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<iostream>
#include<sstream>
#include<cmath>
#include<climits>
#include<string>
#include<map>
#include<queue>
#include<vector>
#include<stack>
#include<set>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
#define pb(a) push_back(a)
#define INF 0x1f1f1f1f
#define lson idx<<1,l,mid
#define rson idx<<1|1,mid+1,r
#define PI  3.1415926535898
template<class T> T min(const T& a,const T& b,const T& c) {
    return min(min(a,b),min(a,c));
}
template<class T> T max(const T& a,const T& b,const T& c) {
    return max(max(a,b),max(a,c));
}
void debug() {
#ifdef ONLINE_JUDGE
#else

    freopen("d:\\in.txt","r",stdin);
   // freopen("d:\\out1.txt","w",stdout);
#endif
}
int getch() {
    int ch;
    while((ch=getchar())!=EOF) {
        if(ch!=' '&&ch!='\n')return ch;
    }
    return EOF;
}

const int MAX_NODE=150;
const int SIGMA_SIZE=26;



int ch[MAX_NODE][SIGMA_SIZE];
int fail[MAX_NODE];
int val[MAX_NODE];
int sz;

struct Matrix
{
    ull da[MAX_NODE][MAX_NODE];
    Matrix(){memset(da,0,sizeof(da));}
    Matrix operator * (const Matrix &ans)
    {
        Matrix res;
        for(int i=0;i<sz;i++)
        {
            for(int j=0;j<sz;j++)
            {
                for(int k=0;k<sz;k++)
                    res.da[i][j]=res.da[i][j]+da[i][k]*ans.da[k][j];
            }
        }
        return res;
    }
    Matrix operator + (const Matrix &ans)
    {
        Matrix res;
        for(int i=0;i<sz;i++)
        {
            for(int j=0;j<sz;j++)
            {
                res.da[i][j]=da[i][j]+ans.da[i][j];
            }
        }
        return res;
    }
};
Matrix base;
ull pow26[32];
Matrix powMatrix[32];

int idx(char c)
{
    return c-'a';
}
void init()
{
    memset(ch[0],0,sizeof(ch[0]));
    val[0]=0;
    sz=1;
}
void insert(const char *s)
{
    int u=0;
    for(int i=0;s[i]!='\0';i++)
    {
        int v=idx(s[i]);
        if(!ch[u][v])
        {
            memset(ch[sz],0,sizeof(ch[sz]));
            val[sz]=0;
            ch[u][v]=sz++;
        }
        u=ch[u][v];
    }
    val[u]=1;
}

void construct()
{
    fail[0]=0;
    queue<int> q;
    for(int c=0;c<SIGMA_SIZE;c++)
        if(ch[0][c]){fail[ch[0][c]]=0;q.push(ch[0][c]);}
    while(!q.empty())
    {
        int r=q.front();q.pop();
        for(int c=0;c<SIGMA_SIZE;c++)
        {
            int u=ch[r][c];
            if(!u){ch[r][c]=ch[fail[r]][c];continue;}
            q.push(u);
            int v=fail[r];
            while(v&&!ch[v][c])v=fail[v];
            fail[u]=ch[v][c];
            val[u]|=val[fail[u]];
        }
    }
}

void constructMatrix()
{
    memset(base.da,0,sizeof(base.da));
    for(int u=0;u<sz;u++)if(!val[u])
    {
        for(int c=0;c<SIGMA_SIZE;c++)
        {
            int v=ch[u][c];
            if(!val[v])
                base.da[u][v]++;
        }
    }
}
void initpow(int n)
{
    int k=31;
    while(!(n&(1<<k)))k--;
    ull x=26;
    Matrix res=base;
    while(k)
    {
        powMatrix[k]=res;
        pow26[k]=x;
        k--;
        if(n&(1<<k))
        {
            x=x*x*26;
            res=res*res*base;
        }else
        {
            x=x*x;
            res=res*res;
        }
    }
    powMatrix[k]=res;
    pow26[k]=x;
}
Matrix MatrixSum(int n,int r)
{
    Matrix res=base;
    int k=31;
    while(!(n&(1<<k)))k--;
    while(k--)
    {
        if(n&(1<<k))
        {
            res=res+res*powMatrix[k+1]+powMatrix[k];
        }else res=res+res*powMatrix[k+1];
    }
    return res;
}

ull sum(int n,int r)
{
    if((n>>r)==1)return 26;
    if((n>>r)%2==0)
    {
        ull res=sum(n,r+1);
        return res+res*pow26[r+1];
    }else
    {
        ull res=sum(n,r+1);
        return res+res*pow26[r+1]+pow26[r];
    }
}

int main()
{
    int n,m;
    while(scanf("%d%d",&n,&m)!=EOF)
    {
        init();
        for(int i=1;i<=n;i++)
        {
            char s[100];
            scanf("%s",s);
            insert(s);
        }
        construct();
        constructMatrix();
        initpow(m);
        Matrix res=MatrixSum(m,0);
        unsigned long long num=0;
        for(int i=0;i<sz;i++)
            num=num+res.da[0][i];
        ull SUM=sum(m,0);
        printf("%I64u\n",SUM-num);
    }
    return 0;
}
View Code

posted on 2013-10-22 16:44  BMan、  阅读(189)  评论(0编辑  收藏  举报

导航