Trie树详解：https://www.cnblogs.com/llllllpppppp/p/9449846.html

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define inf 0x3f3f3f3f
#define mem(a,b) memset(a,b,sizeof(a))
 
bool vis[100005]; 
int trie[505][505];
int pin;

void insert(string s)        //构建Trie数组
{
	int i,u=1;
	for(i=0;i<s.length();i++)
	{
		int t=s[i]-'a';
		if(!trie[u][t])
			trie[u][t]=pin++;
		u=trie[u][t];
	}
	vis[u]=1;
}

int find(string s)           //从Trie树中查找字符串
{
	int i,u=1;
	for(i=0;i<s.length();i++)
	{
		int t=s[i]-'a';
		if(!trie[u][t])
			return 0;
		u=trie[u][t];
	}
	return 1;
}

int main()                    //查找n个字符串中是否含有字符串S2
{
	int n,i;
	string s1,s2;
	pin=0;
	mem(vis,0);
	cin>>n;
	while(n--)
	{
		cin>>s1;
		insert(s1);
	}
	cin>>s2;
	if(find(s2))
		cout<<"YES"<<endl;
	else
		cout<<"NO"<<endl;
	return 0;
}