USACO：Longest Prefix简单dp

/*
ID: Jang Lawrence
PROG: prefix
LANG: C++
*/
#include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
#include<queue>
#define mp make_pair
using 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;
}