USACO：Longest Prefix简单dp

/*ID: Jang LawrencePROG: prefixLANG: C++*/#include<iostream>#include<cstring>#include<cstdio>#include<algorithm>#include<queue>#define mp make_pairusing namespace std;typedef long long lng;int n;string list[201],s,pre,t;bool dp[222222];bool f(){    for(int i=0;i<n;++i)    if(pre==list[i]) return 1;    return 0;}int main(){  #ifndef  DEBUG  freopen("prefix.in","r",stdin);  freopen("prefix.out","w",stdout);  #endif  while(1)  {      cin>>list[n];      if(list[n]==".") break;      n++;  }  while(cin>>t){s+=t;}  dp[0]=1;  for(int i=1,z=s.size();i<=z;++i)  {      for(int j=1;j<=10&&j<=i;++j)     if(dp[i-j]) {pre=s.substr(i-j,j);      if(f()) {dp[i]=1;break;}      }  }  int ans;  for(ans=s.size();;--ans)  if(dp[ans]) break;  printf("%d\n",ans);    return 0;}