POJ2778 DNA Sequence AC自动机，DP，矩阵加速

来源：互联网发布：女生学java 编辑：程序博客网时间：2024/06/08 18:20
题目大意，找长度为n的不包含某些字符串的数目。
#include <iostream>#include <stdio.h>#include <string.h>#include <queue>using namespace std;const int maxn=200;const long long mod=100000;struct node{    int next[4],flag,fail;    void init()    {        for (int i=0;i<4;i++)            next[i]=-1;        fail=-1;        flag=0;    }}node[maxn];char str[20];int s[20];int cnt;long long a[maxn][maxn],ans[maxn][maxn];int n,m;void init(){    cnt=1;    node[0].init();    memset(a,0,sizeof(a));    memset(ans,0,sizeof(ans));    ans[0][0]=1;}void change(char str[],int s[],int len){    for (int i=0;i<len;i++)    {        if (str[i]=='A') s[i]=0;        if (str[i]=='C') s[i]=1;        if (str[i]=='G') s[i]=2;        if (str[i]=='T') s[i]=3;    }}void insert(int s[],int len){    int root=0;    for (int i=0;i<len;i++)    {        if(node[root].next[s[i]]==-1)        {            node[cnt].init();            node[root].next[s[i]]=cnt++;        }        root=node[root].next[s[i]];    }    node[root].flag=1;}void getfail(){    queue<int> q;    q.push(0);    while (!q.empty())    {        int root=q.front();        q.pop();        for (int i=0;i<4;i++)        if (node[root].next[i]!=-1)        {            int now=node[root].next[i];            int tmp=node[root].fail;            while (tmp!=-1&&node[tmp].next[i]==-1)                tmp=node[tmp].fail;            if (tmp!=-1)            {               node[now].fail=node[tmp].next[i];               node[now].flag|=node[node[now].fail].flag;            }            else node[now].fail=0;            q.push(now);        }        else        {            int tmp=node[root].fail;            while (tmp!=0&&node[tmp].next[i]==-1)                tmp=node[tmp].fail;            if (node[tmp].next[i]!=-1)            node[root].next[i]=node[tmp].next[i];            else node[root].next[i]=0;        }    }}void getM(){    for (int i=0;i<cnt;i++)        for (int j=0;j<4;j++)        if (node[node[i].next[j]].flag==0)            a[i][node[i].next[j]]++;}void multiply(){    long long res[200][200];    memset(res,0,sizeof(res));    for (int i=0;i<cnt;i++)      for (int j=0;j<cnt;j++)      for (int k=0;k<cnt;k++)      {          res[i][j]+=a[i][k]*a[k][j];          res[i][j]%=mod;      }    for (int i=0;i<cnt;i++)      for (int j=0;j<cnt;j++)        a[i][j]=res[i][j];}void work(){    long long res[200][200];    memset(res,0,sizeof(res));    for (int i=0;i<cnt;i++)      for (int j=0;j<cnt;j++)      for (int k=0;k<cnt;k++)      {          res[i][j]+=ans[i][k]*a[k][j];          res[i][j]%=mod;      }    for (int i=0;i<cnt;i++)      for (int j=0;j<cnt;j++)        ans[i][j]=res[i][j];}int main(){  //  freopen("in.txt","r",stdin);    while (~scanf("%d%d",&m,&n))    {        init();        for (int i=0;i<m;i++)        {            scanf("%s",str);            change(str,s,strlen(str));            insert(s,strlen(str));        }        getfail();        getM();//        cout<<"hi"<<endl;//        cout<<cnt<<endl;//        for (int i=0;i<cnt;i++)//        {//            for (int j=0;j<4;j++)//            cout<<node[i].next[j]<<" ";//            cout<<node[i].fail<<" "<<node[i].flag;//            cout<<endl;//        }        if (n==0) {cout<<0<<endl;continue;}        while (n>0)        {            if (n%2)            {                work();            }            n/=2;            multiply();        }        long long  res=0;        for (int i=0;i<cnt;i++)        for (int j=0;j<cnt;j++)        if (!node[j].flag)        {            res+=ans[i][j];            res%=mod;        }        cout<<res<<endl;    }    return 0;}
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