RT，我用的不是字典树，但不知道为啥WA了。

#include <bits/stdc++.h>
using namespace std;
string a[10005];
inline bool check(string a,string b){
	for (register int i=0;i<a.size();i++){
		if (a[i]!=b[i]) return 0;
	}
	return 1;
}
int main(){
	std::ios::sync_with_stdio(0);
	int t,es=0;
	int n=0;
	while(cin >> a[++n]){
		if (a[n][0]=='9'){
			n--;
		//	cout << n << endl;
		sort(a+1,a+1+n);
		bool ok=0;
		for (register int i=1;i<=n;i++){
			if (check(a[i],a[i+1])){
				ok=1;
				break;
			}
			cout << a[i] << endl;
		}
		if (ok) printf("Set %d is not immediately decodable\n",++es);
		else  printf("Set %d is immediately decodable\n",++es);
	n=0;
	}
	}
}