hdu 2825 Wireless Password 【ac自动机+dp】

我的第一道ac自动机+dp

学了那么久ac自动机，直到现在才会把它和dp结合在一起

结合在一起也没以前感觉的那么神奇，实际上就是图论中的记忆化搜索，ac自动机是一个图，在这个图上进行dp过程就叫记忆化搜索，和树形dp也挺像的~

#include<iostream>#include<vector>#include<algorithm>#include<cstdio>#include<queue>#include<stack>#include<string>#include<map>#include<set>#include<cmath>#include<cassert>#include<cstring>#include<iomanip>using namespace std;#ifdef _WIN32#define i64 __int64#define out64 "%I64d\n"#define in64 "%I64d"#else#define i64 long long#define out64 "%lld\n"#define in64 "%lld"#endif#define FOR(i,a,b)      for( int i = (a) ; i <= (b) ; i ++)#define FF(i,a)         for( int i = 0 ; i < (a) ; i ++)#define FFD(i,a)        for( int i = (a)-1 ; i >= 0 ; i --)#define S64(a)          scanf(in64,&a)#define SS(a)           scanf("%d",&a)#define LL(a)           ((a)<<1)#define RR(a)           (((a)<<1)+1)#define pb              push_back#define CL(Q)           while(!Q.empty())Q.pop()#define MM(name,what)   memset(name,what,sizeof(name))#define read            freopen("in.txt","r",stdin)#define write           freopen("out.txt","w",stdout)const int inf = 0x3f3f3f3f;const i64 inf64 = 0x3f3f3f3f3f3f3f3fLL;const double oo = 10e9;const double eps = 1e-10;const double pi = acos(-1.0);const int mod = 20090717;const int maxn = 121;const int maxc = 26;const int hashsize = 1<<10;const int head = 0;struct zz{    short to[26];    short fail;    short id;}zx[maxn];struct aa{    int len;    int pos;    int s;}as;int n,m,k,use;string s;int dp[maxc][maxn][hashsize+1]; // len | now | statebool ok[maxn];int fs[maxn];bool hash[maxc][maxn][hashsize+1];char ss[12];inline int get(){    use++;    zx[use].fail = 0;    zx[use].id = -1;    MM(zx[use].to,-1);    return use;}void insert(int id,string& p){    int now = head;    int c;    for(int i=0;i<p.length();i++)    {        c = p[i] - 'a';        if(zx[now].to[c] != -1)        {            now = zx[now].to[c];        }        else        {            zx[now].to[c] = get();            now = zx[now].to[c];        }    }    if(zx[now].id == id)    {        assert(false);    }    zx[now].id = id;    return ;}void ac(){    queue<int>q;    CL(q);    q.push(head);    int now,to,tmp;    while(!q.empty())    {        now = q.front();        q.pop();        for(int u=0;u<maxc;u++) if(zx[now].to[u] != -1)        {            to = zx[now].to[u];            q.push(to);            tmp = now;            while(tmp)            {                tmp = zx[tmp].fail;                if(zx[tmp].to[u]!=-1)                {                    zx[to].fail = zx[tmp].to[u];                    break;                }            }        }    }    return ;}int find(int now){    if(ok[now])    {        return fs[now];    }    else    {        int re = 0;        ok[now] = true;        if(now)        {            if(zx[now].id != -1)            {                re |= 1<<zx[now].id;            }            re |= find(zx[now].fail);        }        fs[now] = re;        return re;    }}void dps(){    dp[0][0][0] = 1;    as.len = 0;    as.pos = 0;    as.s = 0;    queue<aa>q;    CL(q);    q.push(as);    hash[0][0][0] = true;    aa now,to;    int temp;    while(!q.empty())    {        now = q.front();        q.pop();        for(int i=0;i<26;i++)        {            if(zx[now.pos].to[i] != -1)            {                to.pos = zx[now.pos].to[i];                to.s = find(to.pos) | now.s;                to.len = now.len + 1;            }            else            {                temp = now.pos;                while(temp)                {                    temp = zx[temp].fail;                    if(zx[temp].to[i] != -1)                    {                        temp = zx[temp].to[i];                        break;                    }                }                zx[now.pos].to[i] = temp;                to.len = now.len+1;                to.pos = temp;                to.s = find(temp) | now.s;            }            if(to.len <= n)            {                dp[to.len][to.pos][to.s] += dp[now.len][now.pos][now.s];                dp[to.len][to.pos][to.s] %= mod;                if(!hash[to.len][to.pos][to.s])                {                    hash[to.len][to.pos][to.s] = true;                    q.push(to);                }            }        }    }    return ;}int has(int temp){    int re = 0;    for(int i=0;i<m;i++)    {        if(temp & (1<<i))        {            re++;        }    }    return re;}int start(){    ac();    for(int i=0;i<=n;i++)    {        for(int j=0;j<=use;j++)        {            for(int k=0;k<=(1<<m);k++)            {                dp[i][j][k] = 0;                hash[i][j][k] = false;            }        }    }    MM(ok,false);    dps();    int re = 0;    for(int i=0;i<=use;i++)    {        for(int j=0;j<(1<<m);j++)        {            if(has(j)>=k)            {                re += dp[n][i][j];                re %= mod;            }        }    }    return re;}int main(){    while(cin>>n>>m>>k)    {        if(!n && !m & !k) break;        use = -1;        get();        for(int i=0;i<m;i++)        {           // cin>>s;            scanf("%s",ss);            s = ss;            insert(i,s);        }       // cout<<start()<<endl;        printf("%d\n",start());    }    return 0;}