HDU 3689, UVA 11468

AC自動機+機率dp

HDU 3689

#include<algorithm>#include<cstdio>#include<queue>#include<cstring>#include<math.h>using namespace std;int n,nn,m;int ok[200];double pp[200];int next[100][30],fail[100],flag[100],pos;int newnode(){    int i=0;    for(;i<26;i++)next[pos][i]=0;    fail[pos]=flag[pos]=0;    return pos++;}int insert(char * s){    int i,p=0;    for(i=0;s[i];i++){        int k=ok[s[i]];        if(k==-1)return 0;        int &x=next[p][k];        p=x?x:x=newnode();    }    flag[p]=1;    return 1;}void makefail(){    int i;    queue<int>q;    q.push(0);    while(!q.empty()){        int u=q.front();        q.pop();        for(i=0;i<nn;i++){            int v=next[u][i];            if(v==0)next[u][i]=next[fail[u]][i];            else q.push(v);            if(u&&v){                fail[v]=next[fail[u]][i];                flag[v]|=flag[fail[v]];            }        }    }}double dp[1020][100];void dps(){    int i,j,k,p;    double ans=0;    memset(dp,0,sizeof(dp));    dp[0][0]=1;    for(i=1;i<=m;i++){        for(j=0;j<pos-1;j++){            if(fabs(dp[i-1][j])<1e-8)continue;            for(p=0;p<nn;p++){                int v=next[j][p];                dp[i][v]+=dp[i-1][j]*pp[p];            }        }    }    for(i=1;i<=m;i++)        ans+=dp[i][pos-1];    printf("%.2lf",ans*100);    putchar('%');    putchar('\n');}int main(){    int i,k;    char s[100];    double tem;    while(scanf("%d %d",&n,&m)==2){        if(n==0 && m==0)break;        pos=0,newnode();        memset(ok,-1,sizeof(ok));        for(i=0;i<100;i++)pp[i]=0;        k=0;        for(i=1;i<=n;i++){            scanf("%s %lf",s,&tem);            if(ok[s[0]]==-1)                ok[s[0]]=k++;            pp[ok[s[0]]]+=tem;        }        nn=k;        scanf("%s",s);        int len=strlen(s);        if(len>m || insert(s)==0){            printf("0.00");            putchar('%');            putchar('\n');            continue;        }        makefail();        dps();    }}

UVA 11468

#include<algorithm>#include<cstdio>#include<queue>#include<cstring>#include<math.h>#define N 500using namespace std;int nn,m;int ok[200];double pp[200];int next[N][70],fail[N],flag[N],pos;char s[100];int newnode(){    int i=0;    memset(next[pos],0,sizeof(next[pos]));    fail[pos]=flag[pos]=0;    return pos++;}void insert(char * s){    int i,p=0;    for(i=0;s[i];i++){        int k=ok[s[i]];        int &x=next[p][k];        p=x?x:x=newnode();    }    flag[p]=1;}void makefail(){    int i;    queue<int>q;    q.push(0);    while(!q.empty()){        int u=q.front();        q.pop();        for(i=0;i<nn;i++){            int v=next[u][i];            if(v==0)next[u][i]=next[fail[u]][i];            else q.push(v);            if(u&&v){                fail[v]=next[fail[u]][i];                flag[v]|=flag[fail[v]];            }        }    }}double dp[110][N];void dps(){    int i,j,k,p;    double ans=0;    memset(dp,0,sizeof(dp));    dp[0][0]=1;    for(i=1;i<=m;i++){        for(j=0;j<pos;j++){            if(flag[j])continue;            for(p=0;p<nn;p++){                int v=next[j][p];                dp[i][v]+=dp[i-1][j]*pp[p];            }        }    }    for(j=0;j<pos;j++)        if(!flag[j])            ans+=dp[m][j];    printf("%lf\n",ans);}int main(){    int i,k,n,cou;    char s[25][25],str[10];    double tem;    int t,T;    scanf("%d",&T);    for(t=1;t<=T;t++){        scanf("%d",&k);        for(i=0;i<k;i++) scanf("%s",s[i]);        memset(ok,-1,sizeof(ok));        for(i=0;i<100;i++)pp[i]=0;        cou=0;        scanf("%d",&n);        for(i=1;i<=n;i++){            scanf("%s %lf",str,&tem);            if(ok[str[0]]==-1)                ok[str[0]]=cou++;            pp[ok[str[0]]]+=tem;        }        nn=cou;        scanf("%d",&m);        pos=0,newnode();        for(i=0;i<k;i++) insert(s[i]);        makefail();        printf("Case #%d: ",t);        dps();    }}