OJ-Problems-Source/HDOJ/3689_autoAC.cpp
2016-09-04 14:13:02 +08:00

88 lines
2.0 KiB
C++

#include<cstdio>
#include<cstring>
#include<queue>
using namespace std;
#define MAX 1005
int cnt;
struct node
{
int flag;
int next[26],fail;
} head[MAX];
queue<int> q;
double pt[30],dp[MAX][30];
void build(char *s,int idx)
{
int len=strlen(s),k;
for(int i=0; i<len; ++i)
{
k=s[i]-'a';
if(head[idx].next[k]==0)
head[idx].next[k]=(cnt++);
idx=head[idx].next[k];
}
head[idx].flag=1;
}
void build_fail(int idx)
{
int now;
queue<int> q;
head[idx].fail=0;
q.push(idx);
for(; !q.empty();)
{
now=q.front();
q.pop();
for(int i=0; i<26; ++i)
if(head[now].next[i])
{
if(now==0) head[head[now].next[i]].fail=0;
else head[head[now].next[i]].fail=head[head[now].fail].next[i];
q.push(head[now].next[i]);
}
else
{
if(now==0) head[now].next[i]=0;
else head[now].next[i]=head[head[now].fail].next[i];
}
}
}
int main()
{
int n,m,v;
double t;
char s[1005];
for(; scanf("%d%d",&n,&m);)
{
if(n+m==0) break;
memset(pt,0,sizeof(pt));
memset(dp,0,sizeof(dp));
memset(head,0,sizeof(head));
cnt=1;
for(int i=1; i<=n; ++i)
{
scanf("%s%lf",s,&t);
pt[s[0]-'a']=t;
}
scanf("%s",s);
build(s,0);
build_fail(0);
dp[0][0]=1;
for(int i=0; i<m; ++i)
for(int j=0; j<cnt-1; ++j)
if(i>=j)
{
for(int k=0; k<26; ++k)
{
v=head[j].next[k];
dp[i+1][v]+=(dp[i][j]*pt[k]);
}
}
double ans=0;
for(int i=0; i<=m; i++)
ans+=dp[i][cnt-1];
printf("%.2f%%\n",ans*100);
}
return 0;
}