hdu 2825 Wireless Password AC自动机+状态DP

时间卡得紧，写成递推可以做一些优化

//#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=100;
const int SIGMA_SIZE=26;
const int mod = 20090717;

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

void init()
{
    memset(ch[0],0,sizeof(ch[0]));
    sz=1;
    val[0]=0;
}
int idx(char c){return c-'a';}
void insert(const char *s,int k)
{
    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<<k;
}

void construct ()
{
    fail[0]=0;
    queue<int> q;
    for(int c=0;c<SIGMA_SIZE;c++)
    {
        int u=ch[0][c];
        if(u){fail[u]=0;q.push(u);}
    }

    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]];
        }
    }
}

int check[1<<10];
void prework()
{
    for(int st=0;st<(1<<10);st++)
    {
        check[st]=0;
        int nst=st;
        while(nst)
        {
            check[st]+=nst%2;
            nst/=2;
        }
    }
}
int dp[MAX_NODE][26][1<<10];

int DP(int n,int m,int k)
{
    memset(dp,0,sizeof(dp));
    dp[0][0][0]=1;
    for(int i=0,k=0;i<n;i++,k^=1)
    {
        for(int u = 0;u<sz;u++)
        {
            for(int st=0;st<(1<<m);st++)if(dp[u][i][st]>0)
            {
                for(int c=0;c<SIGMA_SIZE;c++)
                {
                    dp[ch[u][c]][i+1][st|val[ch[u][c]]]=(dp[ch[u][c]][i+1][st|val[ch[u][c]]]+dp[u][i][st])%mod;
                }
            }
        }
    }
    int res=0;
    for(int u=0;u<sz;u++)
    {
        for(int st=(1<<k)-1;st<=(1<<m);st++)
            if(check[st]>=k)
                res=(res+dp[u][n][st])%mod;
    }
    return res;
}
int main()
{
    prework();
    int n,m,k;
    while(scanf("%d%d%d",&n,&m,&k)!=EOF&&(n+m+k))
    {
        init();
        for(int i=1;i<=m;i++)
        {
            char buf[15];
            scanf("%s",buf);
            insert(buf,i-1);
        }
        construct();
        int res=DP(n,m,k);
        printf("%d\n",res);
    }
    return 0;
}